Because it's everywhere, has extensive documentation and tutorials, all database tools support it, all relational engines support it, some non-relational engines support it, all programming languages have library support for it, it can be accessed through command line tools as well as graphical interfaces, etc.

You think an industry is going to give up 50 years of infrastructure because some (typically junior) devs think the syntax is "kinda icky"?

> My favorite example which sound easy but isn't - select the row which is MAX(...).

If you look earlier in the comments you will see queries that have "DISTINCT ON" in them. It solves the problem that sounds easy, but actually is pretty easy if you know SQL.