Linux, in general, is excellent for privacy. Period. Like, it literally can't get better than no telemetry.

Regarding Ubuntu, it has had some controversies:

• Amazon Lens is a very significant one. Even prompting Richard Stallman to call it out for spyware.
• The Snap store being proprietary.

I'd argue that the above just makes it hard(er) to trust them.

Consider taking a look at Privacy Guides' recommendations.