TCP is not the only way to ensure integrity, QUIC protocol ensures it, using UDP as transport. This is how all new protocols do it since there's too many hardware and software roadblocks to use anything but TCP and UDP.
The infrastructure inertia part isn't even so much a question of technical infeasibility, but greed. So much spending was slotted to carriers to improve their networks, but instead of investing in capacity and protocol upgrades, it all went to lobbying/exec bonuses.
If SCTP really ran on UDP. I'd have no reason to be salty, because we'd already be using it.
> I'd have no reason to be salty, because we'd already be using it.
Direct OS support is a big deal, and UDP gets messed with too. If someone made SCTP-over-UDP the default mode, while changing nothing else, I don't think it would affect adoption at all.