After they took offense to some of the Wiki pages for... basically absurd reasons, if I recall correctly.
I use a rather heavy-duty adblocker (uBlock Origin) and have been using an adblocker for ages (nothing like having to format your PC due to a pop-up ad infecting your PC with a nasty virus without even clicking it to make you decide you're done with ads) so I didn't notice, but I was indeed put off with many of the accessory things like the sidebar and their social thing.
I did just ignore the stuff I didn't care about, but I tried visiting the Wiki from the phone (which I never do since I tend to do stuff mostly from my computer) and... Damn. It's ridicolous. This is not how I want information about my characters to be stored.
(Fandom doesn't see to like information about my characters either, since when I started making a wiki for mi works they eventually nuked it without warning and without even telling me they did, so it seems the hate i mutual here.)
Considering they seem to be still going down the slippery slope, I wouldn't mind looking for an alternative - and, of course, to prevent the issue of duplicated wikis I would suggest "withering" the Fandom one once the jump is made by slowly deleting pages if we haven't got the possibility to fully nuke it.