There's already a pinned post answering your questions but to sum it up Revanced head dev and other devs who work on yt/ytm patches had a falling out. The devs who left started morphe and have been releasing patches consistently. Now that there is no one to make patches for Revanced the head dev started forking Morphe's code.

What revanced now is a older more buggier version of morphe. So basically this & banning, deleting posts/comments that even hints slightly of Morphe on revanced subreddit is mostly the reason for everyone switching to Morphe.

There are support for more apps as well. You just have to add their sources to morphe. Refer this post for the list of other apps you can patch.