> Even organizations building software full time do not want to run their own servers at this point.
This is almost entirely an educational/labor force issue, combined with a slight preference for the nominal hardware flexibility of cloud setups. The tech community focus from the dawn of the web until today has been overwhelmingly on getting people and tools to be better at creating and managing website content, whereas the traditional sysadmin stuff required to run "your own servers" with contemporary server technology has been viewed with both a level of disdain and also utter intimidation. Finding someone who can do React or Angular for your project might not be trivial, but finding someone who could actually run your servers for you ... much harder.
This is almost entirely an educational/labor force issue, combined with a slight preference for the nominal hardware flexibility of cloud setups. The tech community focus from the dawn of the web until today has been overwhelmingly on getting people and tools to be better at creating and managing website content, whereas the traditional sysadmin stuff required to run "your own servers" with contemporary server technology has been viewed with both a level of disdain and also utter intimidation. Finding someone who can do React or Angular for your project might not be trivial, but finding someone who could actually run your servers for you ... much harder.