- 720p/1080p is counting vertical pixel resolution
- 4k/8k is counting horizontal pixel resolution
- "4k/8k" is not actually 4,000/8,000 horizontal pixels
- Suddenly the "p" becomes irrelevant (Not that most people even knew what it meant to begin with)
- 720/1080/4k/8k totally disregards aspect ratio
- Consumers already have a way to compare, and they're called "megapixels"
- 2.1MP (1080p) and 8.3MP (4k) etc. is a lot more consumer friendly since it's already used for cameras.
Marketing really won at making this a mess.