Which JSON type are you missing? I store and query JSON extensively (probably too extensively) in MySQL and most things work great.
MySQL has had a full-featured native JSON column type since MySQL 5.7 (Oct 2015). Here's the current manual page for MySQL 8: https://dev.mysql.com/doc/refman/8.0/en/json.html
MariaDB does not have a JSON column type, instead aliasing it to LONGTEXT. MariaDB takes an alternative approach of providing JSON manipulation functions which work with stringy types. https://mariadb.com/kb/en/json-data-type/
Note that in some Linux distributions, when you try to install "mysql" packages you instead get "mariadb", so you may need to query the server to see which one it really is!
I plan to use CockroachDB as a distributed data store since it's protocol compatible with Postgres. Still in testing phase, but the deployment is very easy.
My blocker was that I'm using it in part for Postfix maps, and the Postfix pgsql module can't be configured to us anything but LATIN-1 encoding, and Cockroach only supports UTF-8.
I did pick MySQL over Postgres for a old project that I'm currently working on again, the primary reason was easy multi-master replication via galera. I know that Postgres has long had many cluster stories, but I always struggled to even figure out which one was the right choice to make. Most of the clusters I've deployed ended up using DRBD and heartbeat rather than one of the Postgres native options.
As far as advance features, quite a few years ago I was doing this exercise to generate reports on some sample payroll dataset. The expectation was clearly that you would run a query, massage that data in some code, then run a bunch of other queries in that code to further correlate the data. I forget the exact problem that was posed.
I'm not super strong in database advanced features, but in the end I was able to come up with some fairly simple SQL, using materialized views or CTEs or similar, that produced the report entirely using SQL, in a fairly short runtime.
This was my first real experience with using MySQL beyond the basic features it had in decades past, and I was quite impressed with it.