Yeah, that seems to be a valid use case, but like you say, relevant stuff easily gets buried in trash. I don't think it is a uniquely Twitter problem, I think every similar platform would devolve into that. I remember when I was using it regularly, it was similar filled with noise, maybe not as polarized as it is today, but then again, the whole world seems much more polarized.
It's same with Facebook. All they want is to serve you content. I remember back in the day, a fresh Facebook profile had an empty feed. I have an old profile I made and kept for god knows what reason, that has no friends, no pages followed, no groups, nothing, and I still get a bunch of crap on my feed.
I remember when my mother made a profile, basically to keep up with family from another town and abroad, and she was shocked to see a post from a writer who was in hospital battling cancer and was in a very bad shape (you can imagine). Considering my mother was really sick and in a very poor state herself at that time, she couldn't understand why she was seeing that post when she wasn't even following that writer. I could see it really left a terrible mark on her. I tried to get rid of such posts, or any other post that was not from her friends, but to no avail.