For me nothing. I can already torrent a full 4k movie in under 10 minutes with my current connection, which is plenty fast. If everyone else had 1Tb and I could get a movie in 20 seconds or something, okay, fine. That would be kind of neat, I guess, but it wouldn't really be that big of an improvement to my overall life. My vision isn't good enough to appreciate the difference between 4k and 8k, so I wouldn't download 8k versions even if they were available. I'd consider that a waste of disk space.

I might start paying for streaming movies if services would fully buffer an artifact-free copy of the movie on my media player before starting to play the content. I don't think they'd do that though even if I had infinite bandwidth to my house. To save bandwidth and storage costs on their end they're going to continue to enshittify the streams to whatever generally-tolerable trickle people won't cancel a subscription over.

My Zoom calls would be the same. 75% of the people in Zoom calls keep their camera off anyway and hardly ever say anything, so the extra bandwidth wouldn't matter for work.

I generally will continue to avoid any Internet of Shit devices or privacy-ravishing Cloud services, so having extra bandwidth wouldn't impact my propensity to use any of that stuff.

I don't know. I guess I'm not creative enough or prone to use Cloud anything to imagine how my life would get better with 1000x more bandwidth. Maybe some startup would come up with something that would be the next "iPhone moment."