If you really think a "FaceTime dinner" is the same as "going to a restaurant" and "huddling with people", you're very weird. Even though I personally don't care for being around people, I still recognize that there's a huge difference.

No one lives forever. If Covid 19 doesn't do you in, something else will eventually. To compromise on the things you want to do and live the rest of your life in seclusion trying not to get sick just seems rather pathetic to me.

And as for your brother, does he really have much to fear from getting it? Centainly, most people wouldn't want to get it (unless you just want to get it over with so you don't have to worry about it any more). But not wanting to get sick isn't a good reason to tell your mother that she shouldn't have a life.