[jauntywundrkind]

Upload speed seems like a non-concern, just based on time. Even very active people are going to spend like 1% of available time downloading. So effective net upload bandwidth is going to be 100x bigger (times by your connections up/down speed ratio).

So long as people seed for some time, there tends to be amazing availability and absurdly fast speeds.

I'd love exact numbers but my impression is 80%+ of consumer wifi routers ship with upnp-igd and often Apple's nat-pmpd, which means any torrent program you open worth a salt will port-forward just fine. I can't think of the last household wifi I was on that didn't have upnp-igd, it's been so long.

In some ways p2p has been underinvested in because it has worked so well for so long. Various public & private trackers have come and gone but theres been a variety of good-enough options. Tribler pioneered p2p search over BitTorrent a long time ago & some users report that works surprisingly well for them & I think maybe that technique is semi widely done in clients now.

I think the main thing is just getting new folks in the door, and setup to find stuff. Bandwidth & connectivity seem pretty great. But we keep having major trackers collapse, and it's unclear how to get people started & successful.