Then they might simply join another startup or a big tech company as competition for good engineers is fierce. Startups also famously underpay versus larger companies so you need to entice engineers with something.
I mean, seriously, this is a startup killer. Our host wrote an essay a long time ago about beating standard companies stuck in boring old Java or C++ with your fast, agile Python code, but in 2020 it seems to me it's almost more important now to try to convince new startups to be a little more boring. Whatever your special sauce that you're bringing to market is, it isn't (with no disrespect to the relevant communities) that you're bringing in Rust or Nim or whatever for the first time ever, for Maximum Velocity. Just use Python, cloud technologies, and established databases. Win on solving your customer needs.
While by no means is everyone in the world using effective tech stacks well-chosen to meet the needs and without over-privileging "what everyone else is doing and what has always been done", enough people are now that it's probably not a competitive advantage anymore.
Honestly, you can beat most companies in just getting stuff out the door quickly.
(Excuse me, off to file incorporation papers for ZeroNines LLC. Why wonder whether your provider will be up when you can know? Nobody else in the business can make that promise!)
Money may not be the limiting factor for a startup and time is a counter-factual as you don't know the alternative. Had they not been able to hire any engineers they may have taken an extra 2 years to ship the same thing. Or maybe not.
Hiring at startups is time consuming and difficult with heavy competition for good engineers. Salaries lag behind large tech companies and equity may be worth nothing. Scale isn't there so the problems are less interesting than at a larger company. And good engineers can 5x better than average in an early stage startup because there is no process and technical debt is fine (in a larger organization the 10x ones leave havoc in their wake).
That may not be the right decision for a startup to make but there is a logical basis for making it.
New hotness is one way to entice them. Far, far from the only one but it is a tool in the CTO's tool belt.
I've rejected candidates who have been great on their technical skills . . . who I would never want to be making ANY decisions about customers, or the technical direction of the company.
My team right now, for example, had a mantra of "No JS frameworks, just Rails" which was absolutely dreadful. Rails UI is absolutely dreadful. I can't say enough, it is absolutely dreadful. So we recently made the move to use React for more "dynamic" UIs, which has brought up somewhat of a happy medium? React will be here in 5 years, Rails will be here in 5 years, everyone wins.
I hope, but doubt, that will happen before I'm retired or have been ageism'd into something else.
Only the bad ones.
You're also setting up a bill that will come due eventually. I've made some really good money going into companies and ripping out the hot-three-years-ago garbage that some long-gone goof put in. Last time this happened I looked up the responsible party. Turned out he was doing the work so he could give a conference talk on shiny tech. Not long after the talk was done, he took a job somewhere else, leaving his buzzword-compliant half-baked system to rot.