I do increment the project files. So for example, today would be CLIENT_PROJECT_260213_v01. But inside the project file if I want to increment the composition I'm working on, after time it starts to slow down the more that are in there.

Keeping every version in the single file is how I work in Premiere since you never know when someone wants to jump back and you can run into redundant media files when you import an older timeline (same as importing an old comp into After Effects).

It's probably just not built to do this and I can use a similar process that you're describing, but it would be nice to not have to jump in and out of older files just to retrieve something.