How accessible are open-source slack competitors like Mattermost? I feel for you. I'm blind in one eye and am at a pretty high risk of going blind in the other

How accessible are open-source slack competitors like Mattermost? I feel for you. I'm blind in one eye and am at a pretty high risk of going blind in the other because of it. I do my best to make sure the things I build are accessible; it's a real shame that accessibility is typically an afterthought.