I too am a fan of what Oracle did for MySQL. There haven't been any major releases since 2018, though. Since their development process is closed, I am wondering when/if are we going to see MySQL 9 (if it's anything like 8, it's going to be huge).
https://dev.mysql.com/doc/refman/8.0/en/mysql-nutshell.html
MariaDB initially went through a process of adding absolutely everything they could into the database (e.g: many additional storage engines like Cassandra and TokuDB), most of which since have been removed. It felt less like it was driven by a strong engineering process, and more like let's throw everything and see what sticks (not much did).