> a PC laptop with secure boot disabled can't watch 4K Netflix...
It can't? Not a laptop, but my desktop still has L1 without secure boot enabled. Don't have Netflix subscription to actually test your claim but idk what they'd be detecting / requiring outside of that
Also, if you've bought a high-end PC laptop in the past decade, you'd know that you still can't get one without prior research to see if everything actually works with Linux.