A couple things - every jump like that in resolution is about a 10% increase in size at the source level. So 2K is ~250GB, 4K is ~275GB. Haven’t had to deal with 8K myself, yet, but it would be at ~300GB. And then you compress all that for placea like netflix and the size goes down drastically. Add to that codec improvements over time (like x264 -> x265) and you might actually end up with an identical size compressed while carrying 4x more pixels.

HDMI is digital. It doesn’t start failing because of increased bandwidth; there’s nothing consumable. It either works or it doesn’t.