Ehhh flexibility is a good feature to have, but it’s not a requirement for good UX. Good UX should work for both beginner and advanced users, whether you do that through a single UI, different presets, or customizable panels depends on the use case and features available. A good music player for example doesn’t need a highly flexible UI to have good UX.

If anything, a good UX should know what tools people use most and how the rest of the market does theirs to have something that’s transferrable but also that works well with your feature set and brand vision