Well for one we know plenty of technically competent older workers who get passed over in tech and it isn't a zero sum game - in a functioning system there is room for young and old workers and overall success inproving with more workers can make more room. Elected officials are finite and zero sum so the situation isn't comparable even if principles are.

There are also the throughly mixed messages sent. Ageism is enshrined into law even past the threshold of 18. It is just defined with maximum hypocrisy such that a 20 year old is too incapable of drinking while a senile nonegarian year old with Alzheimers severe enough to have the mental capacity of a child is. Now there are obvious dangers to sunsetting rights but that double standard both normalizes the reverse and both equality and spite make "what is good for the goose is good for the gander" viscerally tempting to those who were disadvantaged. Not the best of mentalities but it is easy to see how someone who couldn't rent a car until recently would be less than sympathetic.