I think a lot of it comes down to paperwork burden. It used to be if you were entitled to something there was an office you could sit down in and they had a responsibility to get you want you needed before you left. Now, they send you home with a link to a webpage that doesn't work and a million online forms that time out that you have to fill in perfectly or they get auto-rejected.
I'm dealing with this with a work friend who's trying to apply for medical leave with hostile management. If you can't count on your immediate boss getting you the paperwork you need in a timely manner without throwing a fit because you're "trying to get out of work", it just becomes a million times harder to live a normal life. It used to be that there was a chair somewhere you sat in and could reasonably expect your problems to be solved by the time you stood up again.