MySQL is still a thing because of inertia. Back when projects like Wordpress or MediaWiki were started, MySQL was the only good free option (postgres had a repu

MySQL is still a thing because of inertia. Back when projects like Wordpress or MediaWiki were started, MySQL was the only good free option (postgres had a reputation for being slow back then). As a consequence most of the PHP ecosystem is on MySQL. And despite not being hip in Silicon Valley, PHP makes up a massive portion of the internet. Also MySQL makes some different tradeoffs than other databases, and while some of those may eat your data they can also make MySQL the best choice in some situations. MariaDB is an attempt at a better, freer, faster fork of MySQL, viable as a drop-in replacement. That comes with all the expected drama around the MySQL/MariaDB choice and the companies behind them.