Didn’t catch that part with the disks. But AFAIK even physical disks incur a royalty fee payable to the console maker. Not sure how much that is though.

That being said, only the top notch console models come with disk slots these days. Entry models don’t.

Does the Switch have disks or cartridges, actually?

The Switch has cartridges, a SD Card slot, and internal (unupgradable ~32GB) storage.

Afaik, not every game is sold on a cartridge but I think every single Nintendo produced game is and anything you get from like Target is.

I personally install games to an SD Card but other family members are very big on cartridges since they're not effectively locked to a specific Switch.