How long can I stay on OOS11?

I'm planning to stay on oxygen os 11 for as long as possible. I like oxygen os 12, but me not being able to force 120hz on certain apps (no autoHZ support) is a dealbreaker.

I have an antivirus I pay for (mcafee) which scans new apps i download, and I am very cautious about what i download and install.

How long can I stay on android 11? When android 11 becomes outdated I'll either buy a pixel or just get a custom ROM.