Of course people can use whatever they want. In my case, I think Ubuntu based distros can’t deliver the best performance for gaming because they use older graphics stacks and kernels that, by the way, are configured for generic hardware and performance. On the other hand, I have been using Linux for more than 20 years, so I can take this issues and solve them if they keep appearing.
Yes, there’s no doubt in my mind Nobara is not mature enough and shouldn’t be recommended to novice Linux users/gamers. Using Fedora instead of Nobara, is way easier for a regular user, comparing the upgrade process of both was like night and day.
Xiaomi phones usually get their source code published. From there, you may want to choose a Qualcomm device, for some reason developers prefer these to build device trees for custom ROMs. If you don’t mind having an older phone, you may want to check the list of officially supported phones for reputed custom ROMs like Lineage OS or Pixel Experience and buy one of those. I’m guessing that phones in China are cheap and options are numerous.
I use a VPN. At least I try.