Most of them seem to just generically peter out at the end. Action movies tend to end with generic fight scenes in forgettable industrial settings. Comedies tend to shift from being funny to trying to impart some lame platitudinous lesson. And some movies only exist for the ending, which results in messy or mediocre movies — see, e.g., The Usual Suspects — a cool twist ending in search of a movie.

Too few good ones.

Derailed is a great example of a totally mediocre movie that makes a valiant attempt at redeeming itself by having a good ending. Similar with Vanilla Sky.

Some examples of great recent endings:

Coda - exactly what you expect, but they they do it well and so it lands nicely.
A Sun - terrific, emotionally satisfying
The Kid Detective - A very effective gut punch
The Vast of Night
The Gentlemen - A fun Guy Ritchie everything-comes-together-at-the-end finish
Once Upon a Time in Hollywood - Great sequence
Parasite
Jallikattu - Total craziness
The World is Yours - Terrific bringing together of all the plot strands
Phoenix
Paddington 2 - Obviously
1945
One Cut of the Dead - Final third is one of the best jobs of delivering on everything that preceding it that I've seen

Comedy endings that really work well seem particularly tough. I think Step Brothers might have the best I can remember — the Catalina Wine Mixer manages to bring everything back together while also being one of the funniest parts of the movie.