There's a belief floating around leadership circles. It goes something like: "Why invest in training? They'll leave and take the knowledge somewhere else."
I've heard it from CTOs. I've heard it from engineering managers. I've thought it myself.
But a nastier reality hides behind the fear... one nobody talks about at board meetings or quarterly reviews.
Trained people leaving isn't the real cost. Untrained people staying is.
The People Who Stay, Broken
Gallup's research on what they call "The Great Detachment" puts it in hard numbers. Only 30% of employees feel connected to their company's mission, down from 38% in 2021. And 55% of employees don't know what's expected of them at work.
These aren't people who've checked out and handed in their notice. They're still showing up. Still collecting their salary. Still attending standups, grinding through tickets... and mentally, they've already moved on.
This is the slow rot untrained, stagnant teams produce. Not sudden exits. Gradual decay.
I've managed teams where this was the problem we weren't naming. Engineers in the same role for three years, doing the same work, with no new challenges, no growth pathway, no indication their skills mattered beyond the next sprint. They weren't bad people. They were people told, through action rather than words, their development wasn't worth the investment.
So they stopped developing. And they stayed.
Why Managers Don't Train
The arguments against L&D investment are familiar:
"We don't have the budget." Training is usually the first line item cut when things tighten. It's a soft number. Easy to defer. The business won't immediately collapse without it, so it becomes the sacrifice.
"We don't have the time." The team is underwater. Three critical deliveries and a migration are hanging over everyone. This isn't the right moment for training.
"They'll leave anyway." The fear underneath. What if we train them and a competitor snaps them up?
All three make a certain kind of short-term sense. None of them hold up past the next 12 months.
The "no budget" argument ignores what non-training costs. According to Hone HQ, training programs reduce employee turnover by an average of 43%. A 1,000-person company saves around $5.9 million from the turnover reduction alone. The question isn't whether training costs money. It's whether skipping it costs more.
The "no time" argument is self-sealing. Teams always underwater are usually teams without the skills to get ahead of the work. Cutting training to save time in the short term guarantees being underwater again next quarter.
I'll come back to the "they'll leave anyway" fear.
The Actual Cost of Stagnant Teams
Here's what no one puts in the spreadsheet: the cost of a mediocre team staying.
A disengaged engineer who stays is expensive in ways not showing up on the P&L. They introduce technical debt. They slow the onboarding of newer team members. They resist change... not because they're obstinate, but because change feels threatening when you haven't been growing alongside it. They drag standups. They produce work technically passing review but lacking creative energy.
And they hire in their own image when they get the chance.
Hone's research shows companies investing in training see profits rise by 23% and productivity go up 18%. The difference isn't incidental. It's the gap between a team operating at baseline and a team growing.
The irony is managers often stifle growth while trying to protect the business. There's a well-documented pattern in tech leadership where being overly solution-focused, jumping in with answers because it feels efficient, robs your team of the development they need. The instinct to protect feels safe. It isn't.
"What If They Leave?"
Right. Back to the fear.
If you train your engineers and they leave for a better role elsewhere, good. Here's why.
First, you built something. An engineer leaving after growing under your leadership is an ambassador for your team culture. They'll refer talent. They'll remember you well. Tech is a small world.
Second, the alternative isn't "they stay and are loyal." The alternative is they stay and are disengaged. You've lost the productivity either way... except in the disengaged version, you're still paying for it.
Third, a team culture investing in people attracts people who want to grow. Those are the people you want to hire. People wanting to grow are the ones shipping things, questioning assumptions, and staying engaged when the work gets hard.
The fear of training people who leave is a fear of investing in your people at all. And the fear costs you more than the investment ever would.
What Good Development Looks Like in Tech
Not sending engineers to a two-day conference and calling it done. It's a tick-box exercise and everyone knows it.
Good development in engineering teams looks like this:
Making space for deliberate practice. Not every sprint is a race. Carving out time for engineers to learn new patterns, experiment with new tools, or pair on something outside their comfort zone produces engineers who grow.
Treating learning as a team practice, not a solo activity. The teams growing fastest are the ones where knowledge sharing is part of the rhythm. Not formal training sessions... informal lunch-and-learns. Engineers teaching engineers. Curiosity treated as a professional skill.
Giving people work stretching them, not work fitting their current profile. The easiest path is assigning work to whoever already knows how to do it. The most effective path is assigning work slightly above what someone knows, with support behind them.
Being honest about career pathways. Engineers not seeing a future on your team will start looking for one elsewhere. The conversation about where this is going? Have it. You don't lose people to the conversation. You lose them to not having it.
The Manager's Real Job
There's a version of engineering leadership built around protecting delivery: hit the dates, keep the lights on, clear the blockers. This version produces delivery in the short term and stagnation in the long term.
The better version treats team capability as a product needing ongoing investment. Your engineers' skills are the asset. If you're not growing the asset, you're depreciating it.
I've seen this pattern at every scale, from small start-up engineering teams to large enterprise departments. Managers who never "had time" for development were the ones dealing with the most chaos 18 months later. Managers treating development as non-negotiable had teams looking different... more confident, more capable, quicker, and yes, sometimes smaller because some of those people got promoted or moved on.
Good. Healthy. Worth aiming for.
One Question
Before your next sprint planning, ask yourself honestly: am I growing the people on my team, or am I extracting from them?
If your answer is closer to "extracting"... look hard at what the cost will be 12 months from now. Because the bill for skipping development doesn't arrive immediately. It arrives when you're wondering why your best engineers are emotionally checked out, your delivery is slower than it should be, and your team feels stuck.
The invoice was always coming. You chose when it would land.