You are right, but many of these colors are physically dim and much harder to notice than the HDR "pop" of extremely bright colors.

YouTube has surprisingly great support for HDR and Wide Color Gamut. There's some utterly breathtaking 4k 60fps HDR WCG videos of Japanese cities I've been watching. The only downside is you practically need a supercomputer to decode them in realtime.

Many games are also getting "definitive edition" remasters with HDR and they look glorious.

Getting a quality HDR screen was a bigger upgrade for me than 1080p->4k . There's simply a shitload of colors that older monitors can't produce