I like Mission Space alright, it is just a worse attraction compared to what was in its place before. A similar problem happened with Stitch. Alien Encounter was definitely the better attraction story wise. But it wasn’t popular with the average guest just like Horizons towards the end of its existence. Mission Space probably has just as much popularity now as Horizons did in its final years though. While I enjoy a ride on it every few years, I am surprised it still exists in its same form, more or less, after 20 years.
Also I prefer BLSRS over TSMM, but that’s probably because Buzz Lightyear was my favorite character as a kid and I have fond memories of riding it with my dad, I’ve only done the latter a few times because it was so popular for years that you basically had to rope drop it or wait 2 hours to ride it and while it’s a fun ride, it’s not worth that. The “new” theater and SDD alleviated a lot of that. Buzz could definitely be something else, but Disney needs to address MILF and SGE first and none of them seem to be a priority for them. Buzz gets pretty sizable wait times nowadays anyway, but that could be partly due to downtime on other attractions.