I think framing things as some sort of discrimination, "ageism" in this case, constantly works to avoid actually approaching the question of why things are the way they are by instead simply blaming prejudice or other unreasonable issues. So for instance a few random issues, or perceived issues:

- Older workers are genuinely more well qualified and are going to demand a substantially higher salary than younger workers.

- Younger workers are less likely to have family and other outside commitments that may take priority over work related issues.

- Younger workers may still see things like web technologies becoming obsoleted every few years as an exciting and invigorating thing, anxious to learn the next big thing (that will then be obsolete 3 years later).

- Pair the above two to yield the fact that younger workers may be more inclined to spend their own time pursuing interests that could improve their perceived value as an employee.

- Older workers have a better understanding of employee-employer relationships and may be less inclined to accept unreasonable 'friendly nudges' that can encourage younger workers to "give 110%" [without corresponding compensation]

- Older workers are going to have a better idea of what they're worth than younger workers who will, almost invariably, dramatically lowball their worth. This gets back to point #1, but also arises in things like contract negotiations.

"Ageism" suggests people are discriminating against individuals because of their age. Choosing to hire people who have certain characteristics, even when those characteristics are less prevalent in older individuals, is in no way discriminatory. And in framing it as ageism we ignore why people may prefer younger workers and the discussion of whether these reason are legitimate.

I half wish we had a way to completely remove any identity related characteristic from the hiring process and end once and for all any allegations of discrimination. Full on voice scrambling, audio only discussion, and VR in lieu of on-site interviews. Only downside would be a necessary restriction on certain topics that could implicitly reveal identifying information. It'd be like the dating shows of the 90s. After you'd made an offer that was accepted, the block would turn and you'd finally get meet your new employee.