I do a backup and full factory reset once every major OS version releases, but only then.
I have never had any issues, bugs nor anything similar that's widely reported when new versions of iOS are released, and I believe that's because upgrading always leave remnants of lingering trash. But that's me.
Synch with a cable, let it finish, check the option to synch over wifi, save it, enjoy.
I find really funny that this conversation exists around the phone universally thought to be overpriced, made by a pretentious company, and regarded as inferior and behind the competition in innovation because it's seen as a fashion item instead of a phone.
I would say that, like owning an iPhone, buying Casetify is reduced to: people like it and can afford it. That's pretty much it.
I do believe they are super overpriced tho, not defending them. But reading all the condescending comments has been truly amusing, haha.
To be completely honest, there's barely any difference ever since the X. Incremental upgrades will get you a better camera, but the XR had such a great battery life and remains super snappy, so if you aren't really a camera guy there won't be a lot new besides ProMotion and Dynamic Island.