Why did postgres win vs mysql?

They did? By social media? According to a lot of social media devs Java is also “dead”.

Having said that the issue is MySql / Mariadb is moving more and more behind commercial products e.g. Galera and Heatwave. Postgres continues to be the open community effort.

But hence the divide you see. Large companies. Real traffic use pragmatic solutions to make money. The tutorial developers and hype does whatever.