> In a datagram-first world we would have no issue bonding any number of data links with very high efficiency or seamlessly roaming across network boundaries without dropping connections. Many types of applications can handle out-of-order frames with zero overhead and would work much faster if written for the UDP model.

So your argument is that software isn’t written well because TCP is too convenient, but we’re supposed to believe that a substantially more complicated datagram-first world would have perfectly robust and efficient software?

In practice, moving to less reliable transports doesn’t make software automatically more reliable or more efficient. It actually introduces a huge number of failure modes and complexities that teams would have to deal with.