My last one was a Chaos Communication Congress where I knew I'd be in my room exactly 6h-8h per night for like 4 days. All I really need is a bed and a shower. In the end I chose a hostel for that but if I don't use 90% of the amenities of the hotel (not even storing my luggage there), why would I pay that high amount?
Maybe it's too situational, maybe what I would have wanted was a capsule hotel with a tiny room with a bed (or something to put my sleeping bag on), and it wouldn't have to be the same one every night if I had a locker there.
Disclaimer: Have never used AirBnb or alternatives before, but I think it has its uses. For example sharing a flat with 6 people is sometimes half the cost of 3-4 hotel rooms (depending on how you can split)