I find it really dispiriting and alienating that so many of us are fine not making an effort to hinder the spread of a still-deadly virus
I'm not fine about it, but there has to be a risk/benefit analysis as well as a response to other people's preferences.
The only way I can think about risk/benefit is through my experience with Covid, which suggests I'm not at greater risk than anyone else my age. The downside of not masking was that I got infected twice and felt really strange for a few days, though not especially ill. The upside is getting to play music I love with small groups of people, the benefits of which are huge to someone who's limited by ME/CFS.
There's always a risk the next infection could be much worse. But there's an equally real risk that it isn't, and by trying to avoid it I miss out on a lot of enjoyment. I'm a wheelchair user in my mid-60s and I've been ill for 48 years. Part of my calculation is asking, how much time is there left when I'll still able to drive a van and do things I really value? It's not only being at increasing risk of serious illnesses like cancer as you age, it's that ME/CFS is unpredictable. Even if I stayed in and took every possible shielding precaution, it could still leave me severely ill from tomorrow. It doesn't need any help from Covid.
As for other people's preferences, only two of the others in the music groups can't wear masks because they play wind instruments. The others could, as but none of them actually does, I'm not imposing my choice on them. If one person did want to mask, we'd do likewise or sit 10+ metres away.
It is tough, specially for indoor activities, and my feelings about it have changed over time. If there'd been a prospect of Covid dying down, the way 'flu pandemics seem to, I feel sure I'd have continued with precautions until it did. But with no end in sight, it's just reviewing what's happening currently and trying to be as considerate as you can.