On prem / self-hosted used to be the norm.

The "cloud" rose to prominence from a small period of tiem where Amazon had a lot of extra cloud capacity outside of Black Friday, etc, and linux networking issues that needed architecture to be a certain way.

Those linux networking issues have been long since solved, but the "cloud" was discovered to be incredibly profitable and sticky in the name of convenience and proliferated.

A lot of the "cloud" software is open source software that was packaged to have a web and api front end, and that service renamed to something specific to AWS, etc.