MySQL is open-source. There are a lot of open-source communities trying to come up with their own patches, and to come up with their own features, which help MySQL develop faster than traditional databases like Oracle, which is closed source.
The solution is also compatible with a lot of other databases, like Percona, and it's compatible with MariaDB. It's also compatible with a lot of other shared database solutions.
Since MySQL is mostly used as a relational database in a lot of organizations, a lot of other solutions are being merged with MySQL and it's a rather easy process.
Unlike a lot of closed source services, the new features are solely based on customer feedback. The customer feedback of open source is way larger than the closed source application.