

Because the Linux Foundation says so. I would guess it’s because most of the relevant tech started as cloud products or services and got generalised, such as Kubernetes (the big one in CNCF).
The naming wasn’t up to Bazzite or uBlue to decide, that’s for sure, and the term “cloud native” has won the mindshare of developers.
The irony hits hard when you’re logging into an on-prem Kubernetes cluster in your company’s wholly owned data centre. At that point, “cloud” isn’t even someone else’s computer (as the FSF would say).
Since Mint is based on a stable distro, it’ll be running older software that won’t support your newer hardware well, and you’re experiencing that firsthand.
Try Fedora, Bazzite, OpenSUSE Tumbleweed, or anything else that’s more bleeding edge – they’re still very usable and reliable, it’s just that stable distros like Mint and Debian are “stable and reliable” overkill.
Edit: and if you’re wondering why this wasn’t mentioned to you from the start, the answer is likely that these distros tend to be: