Don't Look Up was a good movie concept, which isn't necessarily the same thing as a good movie.
It started off how it should, and progressively (no pun intended) got more nakidly partisan as it went on, it's metaphors and connections becoming increasingly obvious, lazy, and less interesting. It's humor died down as everyone realized that the same joke was just stretched out for too long to remain funny without adding a second one.
In a cycle of the extemes on both ends denying science by being either dismissive or catastrophist, aided by cultural considerations and misinformation... it merely picked one side as the problem and forgot to be introspective. In real life, both standard authorities and conspiracy kooks lied to us and demanded fielty to the tribe, and those with the greatest philosophical connections to it won't find any challenge to their thinking rather than affirmation of their righteousness.
Don't get me wrong... in some ways it was a great movie. I actually think it's worth watching, and it wasn't a waste of my time. It's just that what it wasted so much of was it's own potential (everything from premise to cast to budget to relatively decent writing and directing at times). It was the equivalent of anything still halfway decent that Metallica released post black album. Despite having no predecessor (unless you count Melancholia), it was still past it's own prime.
There were parts that, despite it's flaws, made me smile or were incredibly well done. It was aided by much more than just a good conept. It deserves some credit... just not as much as it should be getting.