Startup founders don't care about providing careers per-se, but they care about the clout and connections that comes from founding a company with 100+ engineers mentioned at every cloud provider's conference as opposed to a scrappy garage with 3 greybeards hacking away Perl code running on rusty bare-metal.

CTOs and engineering managers care about their own visibility at said cloud provider's conference so it gives them bonus points for their next gig.

Individual contributors want to take the place of the aforementioned engineering manager/CTO so they'll double-down and learn the current stack and "best practices". They may not even be aware that there's any other way or how unefficient it is, as they've started their career during this madness.

If any of those people have stock options, keeping low and going with the flow is a sensible strategy if they don't want to lose them by getting pushed out for speaking against the groupthink.

There's rarely explicit malice involved at any specific stage - it's a market-level problem. The music will stop at some point though and we'll see a readjustment.