I think that in most aspects message walls are better than talk pages (mostly because they're easier to use and make the wiki more accessible to people who aren't used to Wikipedia-style talk page). That being said, it's incredibly frustrating that checking message wall history is so difficult/impossible(?), with which I've had some bad experiences and that just kind of sours the whole thing for me. I know that as an admin I can see everything that's happening over the wiki anyways, but I want everyone to be able to check the history of all discussions that happen. The ability to delete messages from your message wall without it leaving a trace for regular users just doesn't sit well with me.
Edit to add: the wiki is autistic-characters.fandom.com