This is the old epic circuit switching vs packet switching religious divide dressed up in new clothing. The reason why data networking is done in "declarative"

This is the old epic circuit switching vs packet switching religious divide dressed up in new clothing. The reason why data networking is done in "declarative" mode rather than "imperative" aka centralised mode, is that centralised systems can't scale - or they can scale - but not to the degree required for planetary communication of seemingly infinite quantities of cat videos. Mathematically, it's not just that the difference in the available real time information capacity is orders of magnitude, but that there is a reachable capacity for very large distributed systems, while all centralised systems are necessarily limited by the centre. The tools are light years ahead of where they used to be, but you still have to able to use them, and deal with users who at no time want to acknowledge that their application has to be a good network citizen. Just like real life really.