I agree with you that pro-rata streaming royalties are not ideal. DSPs like Deezer do have 'artist centric' royalty systems, which I think are great.

That being said, the MLC has been holding this money for 6 years, and by law (The Music Modernization Act 2018), they can't hold it forever, so they have to disperse it somehow. So the best thing for artists to do here is go register their songs so they get their money.