In my humble opinion, TERFs have improved feminism. Obviously not all the extreme radical ones on tumblr that deliberately make themselves physically repulsive to "own the patriarchy" or whatever, but on the whole they've made me care much more about women's sex-based rights. I used to be a big proponent of the anti-feminism train around the Gamergate era when feminism was exclusively about complaining about men and non-issues in the first world, but whether it be the change in modern feminism or me just getting older, I've really come to care about a lot of TERF talking points. I'm still a bit hesitant to loudly and proudly call myself a feminist because of the negative connotations around it (even in this thread people assume feminist=man-hating dyke) but I would still consider myself one almost exclusively due to agreeing with many TERF views. I guess my biggest complaint about the term "TERF" is that it implied you have to be a radical feminist to be trans exclusionary, and that doesn't fit me at all.