should i update from catalina to ventura

Do you need something form Ventura?

Does Catalina do everything you need or want?

Do you have a supported Mac that can Ventura?

If you have a supported Mac it's always a good idea to keep your Mac up to date, to get the most recent security updates.

But you are entirely free to not do so, if you don't require anything in Ventura, and are aware of the security issues not being addressed by not updating.

Personally, I would, if for no other reason than to have the current security updates in Safari.