I guess for companies that have unlimited positions open this could help. But I feel like most companies hire to fill a specific post, and the most obvious reas

I guess for companies that have unlimited positions open this could help. But I feel like most companies hire to fill a specific post, and the most obvious reason for not being hired, is that they hired someone else. As an employer I have been in a situation where we had 3 perfectly good candidates for s position, any of the 3 would have been fine at the job, but there's only one post. There was no reason for rejecting 2 of them other than there was only one post to fill. While we didn't have discrimination issues to deal with there, it would be hard to show (if there had been) that we were being ageist or whatever. I can completely see though that hiring someone at say 30 may be more attractive than hiring a 58 year old. I might feel that a 58 year old will retire soon (so I have to hire all over again), or that they might have a "don't tell me how to do it, I've been doing this for 30 years" attitude, which can be unhelpful. That's balanced against greater experience meaning they should be better at the actual job. I can certainly see how over 55 makes you less attractive than compeditors for the spot.