I’ve heard HDR10+ GAMING is 10-bit and not 12-bit. Doesn’t that make it inferior?

No. The HDR10+ GAMING specification is open for 10-bit color or higher — it is not capped at 10-bit. 10-bit already reproduces over 1 billion shades, more than the human eye can distinguish in a single image and more than any current consumer gaming display can physically reproduce. Every certified HDR10+ GAMING display today uses a 10-bit panel, so there’s no practical difference in what appears on screen. The “12-bit” figure sometimes cited in marketing refers to a theoretical maximum that isn’t used by gaming displays today. The specification is not limited to 10-bit.