Building without ice scales was hell, building without fur coat was mildly annoying but easily doable. As such, I think ice scales definitely needs to go. It warps the metagame around it to an absurd extent, rendering essentially all other forms of walling special pokemon irrelevant. In addition to the normal negative of overcentralization, it is also so much better at this task that matches often come down to how your breakers match up against their ice scales user; if you don't have a good load into their scales, you're entirely reliant on physical mons to make progress, and if you do they cant do shit to stop you.
Fur coat, meanwhile, has plenty of real competition. There are some pokemon, like ceruledge, that you can basically only wall with FC, but they're both fewer in number than the scales equivalent and there are other alternatives for specific ones if you end up with your FC of choice losing to one of them. I've also run FC no recovery tanks and had both healthy interactions and not spent long bemoaning the lack of defensive core the way I did for scales. I might change my mind and want it suspected again in a few months (Once we've banned the dumb special attackers ice scales has been papering over and have a more free meta) but for the current moment I will be voting DNB on fur coat.