Feels wrong to have them seperate. If we could ad one class that is for all of them would be nice.

yeah, i think it'd be nice to have as an option, if not the default

I think given the limitations of the site, we tend to like them split because if we have all classes in the same category you end up with people getting stuck and burnt out playing just the meta class, if new people come on the scene and want to run their class, but it happens to be the slowest they tend to stay interested. having each class be its own section lets people be the "fastest" in their chosen field, and opens up more avenue to avoid burning out "just" running the meta class to get the fastest time.

If we look at "Risk of Rain 2"(a class based rouge-like), we can see that they use filters instead of different sections. Can't we adopt a similar approach?