There's definitely interest in both, but oftentimes for what I would argue are the wrong reasons. MySQL and PostgreSQL scale to a point but with complexity and data isolation limitations, but they will be always popular because of their longevity. Some NoSQL options scale better horizontally but the limitations of isolation levels are even more significant. Just because most of them now can handle ACID transactions and some form of joins does not mean they can handle strict serialization at scale. There are some, like Fauna, that do, however.

My experience is that MySQL scales as high as you need it when coupled with Vitess, because most data schemas can be sharded, and you can scale each shard vertically enough for all the workloads I've seen.