I had one when I was off with my hip, tbh it was all very pleasant and let me get a few formal digs in at my boss who was being an arse. But there’s not much you can do to argue with a broken hip. It was mostly box-ticking and the aforementioned “making sure we don’t get sued”
OTOH, a good friend of mine was off long-term with depression, and decided he just didn’t want work in his house, so he came into the office and I joined him as witness. Well, that was the idea anyway. In practice, I ended up kicking the HR people out of the meeting, as they were simply bullies and they’d reduced him to tears after about 5 minutes with statements like “Really, your depression is nothing to do with your work, it’s probably from your family background or something isn’t it” and “If I wasn’t able to do my job, I wouldn’t go off sick, I’d resign”. One of them needed a bit of physical encouragement to get him out of the office. All ended up turning into a big payout to avoid a constructive dismissal case.
And that’s where it can get a bit troublesome, for the rest of my time in that particular team I had a pretty difficult relationship with our line manager and with our HR team- he’d already left. But tbh I wouldn’t change a thing, sometimes it felt like the one good thing I did in that job!