Glass Onion complaints aren't without basis.
https://uproxx.com/viral/ben-shapiro-glass-onion-complains-deceptive-plotting-twitter-reactions/
Shapiro is not known for being a movie critic as opposed to political commentary, but his complaints about Glass Onion are kinda right..
Glass Onion was boring, in part because Johnson as per usual, didn't bother developing or providing clues to the eventual "twist" and had to retrofit that narrative into the movie in Act II/III flashback.
The Elon Musk parallel was as obvious as it was kind of dumb, but it also meant that anyone with a brain should have spotted the "real killer" from the outset.
The fact that people now get paid as "journalists" to "report" on what reply guys say on Twitter instead of discussing anything of substance is sad, but here's a case where the critics of the critic are mostly wrong.
Shapiro isn't a brilliant movie critic, to be sure, but I think he was reacting to real issues in the script.
On a bigger note, Rian Johnson just isn't that smart and isn't nearly as talented a director as he seems to imagine himself to be. Neither Glass Onion nor Knives Out are particularly good mysteries and both rely more on "surprises" that aren't actually set up effectively, rather than revealing information that the audience should have caught if they were paying attention.
SPOILER
.
.
.
.
.
The big reveal is that Janelle Monae's character, Andi Brand, had a twin sister and thus we were really investigating not-Elon Musk for her murder, using the unknown sister to trick all the guests on the island into revealing information to Detective Blanc. But this relationship is never subtly mentioned earlier or offered as a seemingly-irrelevant fact, and all we know about Andi is that she co-founded the tech company and then had a falling out with not-Elon Musk.
The twin sister gag is the kind of "twist" a dumb soap opera would use.