Sci-fi movie about people who shrink themselves to save money

So the protagonists are a straight couple that i think had just gotten married. Apparently in this universe the technology of shrinking people is new and there’s some kind of laboratory that is offering the service of getting radically shrinked so people can become richer (resourses would be cheaper if they’re really small, ik this logic doesn’t make sense if everyone does it but that’s what they said in the movie). A lot of people ended up getting this done, but others didn’t because they were scared of it.
The couple ends up going to some sort of hospital to do this, if i’m not wrong they got their heads shaved for it. They show a scene with a bunch of people bald and unconcious in hospital beds, one of those people being the wife. They do the proceeding on her. this scene is kind of creepy though i can’t even remember if they showed how.
The husband i think got it done after her in a different lot so they had to get separated for a while.
I don’t remember if they show when the woman is introduced in the “tiny world” with the other tiny people, but they show the guy being lead to his new mansion (remember, everyone in this world is rich and doesn’t work bc with their savings they can mantain themselves for life). I don’t even remember if I got to see the wife again, next thing I remember is that the husband was in a party in the neightbour’s mansion, without the wife.

A lot happens then i guess, but i forgot. What’s next is completely disconnected to the beggining and it’s almost like another whole movie.

Almost at the end, the guy is in some sort of boat chatting with a group people about the end of the world. It cuts to another scene where a selected group of people are going “underground”(not sure about that word) to preserve human kind, someway they still get sunlight and they carry animals with them to survive. The guy gets selected.

That’s it. That’s the end. I didn’t said it was gonna be a good movie.

Thanks for reading!