OP:
You're going to have to provide more information.
What Mac do you have?
What year was it made?
How much free space is on your drive?
It seems like with Monterey, Apple requires A LOT MORE FREE SPACE on the user drive to do upgrades. By "user drive" I mean the drive that is named by default "Macintosh HD Data".
Not sure why, but I'm thinking that the "secure system volume" is actually "reconstructed" in a "working space" on "Macintosh HD Data", and then it is "copied over" the existing secure system volume (which is normally located on the Macintosh HD volume). I could be wrong.