Missing the most important steps, it has caused me a lot of trouble, pls update the doc ASAP!

Same here. It's like literally the most important steps are missing.

People don't poop your pants. It's largely the same as before:
ng update @angular/core@16 @angular/cli@16, then commit, then ng update @angular/material@16 (if you use material)

It's been three months, and only a small piece of documentation needs to be updated. Can anyone tell me what's wrong? Does the Angular team still exist?

On the other hand if you choose to upgrade from 14 to 15 it shows commands to migrate to 16 and 17 at the bottom of the page...

Almost a year now, and the commands are still not showing properly (ex : from angular 16 to 17 the Angular Material upgrade command is not showing if you check "I use Angular Material")