Regardless of popularity, idk, Postgres feels nicer to use for me.
n.b. PgDog isn't an extension
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.
If your situation doesn't require specialized features of a particular database, then it doesn't really matter. Just pick one. There's too much premature optimization in the world.
If your situation does require something that one database or another excels at, then be grateful that there isn't really such thing as a winner and you can pick the one that works best for your context.