The four to six hours of 30/45/60 minute meetings (that always seem to go over by some unknown amount) slays me regardless of whether I'm actively participating or not.
It's easier if you're a morning person, since you can do all of your "life stuff" before work. However, I'm not (and not for lack of trying), so it feels like I'm confined to my very nice office chair and desk for hours on end. (Unsurprisingly, there's a lot of pressure to work nights and weekends to catch up. This is much easier to do when work is life and life is work. I refuse to do this, even if it means I stay perpetually behind.)
(I could do walking meetings, and I do that sometimes when I know I'll be a passive participant. However, what often happens is this: I finish a meeting, then spend the "free" time between meetings doing follow up from the previous meeting, then I join the next meeting, etc. ad nauseum.)
Meanwhile, I have no problems being in all-day meetings when I'm at customer sites. It feels much, much easier.
For me, a big part of it is environment. When I'm home, I want to do "home" stuff: go to the gym, clean up around the house, walk to a coffee shop or brewery, etc. Being glued to a chair inhibits all of that, and having to talk at your screen for hours at a time is extremely draining (for me). However, when I'm in an "office", I'm in work mode. I'm locked in. It's much easier for me to focus on work things this way.