I truly believe most software development careers die at 35 or 40 years old max. Currently looking to jump to something else because this field does not like experience. People say they want experienced people, but they don't hire them and still go with the 1-10 years interval.
Don't jump! ;). Perhaps look at more sensible/ laid back places in public sector? e:g gov't, academia, they value experience. There's plenty of threads on HN about ageism and how to cope in the tech industry as you get older, plenty of comments from really old programmers. Its totally do-able. I think the reason you see some people's careers "die" is - they lost their technical edge due to things like (1) doing too much management and not enough coding at work (2) trying to chase too much rapidly changing tech (3) simply burning out from overwork and not enough holidays (4) picking the wrong tech to invest in e:g something with vendor lock-in. Open source projects are a better investment. Certain skills gonna be here for ever, others not. Its a meta-skill to know how to "back the right horse".
Yeah I think this is kinda true.
My argument would be that "kinda". is nuanced. ;) Its true only if one doesn't take action to mitigate it. (IMHO, of course, but as someone over 40 )