I'm almost 40 and are constantly getting harassed by recruiters.
My mate in his 60s not long ago got hired for a software developer role, and easily at that. Two interviews and he got an offer.
Another mate near 40 stepped back from manager type role into a developer role, and his age is not an issue.
SV start-ups need bright shiny twenty-somethings for their "About us" pages and their IG lifestyle feed, with a few wise old thirty-somethings to ride herd on them.
It leaves room for the forty-something and fifty-something VCs to do what they enjoy, which is pretending to be the team coach.
Put in some wrinkly old guys - or worse, some old women - and there goes your brand identity.
Only result of this is to repeat mistakes over and over again...
I am 48 and having a blast in my career now, I am getting my hands on all sorts of interesting things to learn.
The only people who I have seen struggle with this are those who just go stale. I have friend who is a C++ programmer, and for 30 years all he has worked on is some logic controller software used in trains and energy systems. He is getting close to retirement, but if things go tits up due to COVIDs impact, he will very likely be unemployable. Me on the other hand. I get daily connect requests and job interests put my way on linked in.