A company that I work for was in the beta of serverless for MySQL, and we currently use it for both dev and production workloads. We're a startup, so it definitely simplifies devops for us, but personally I think you're better off just running a large RDS instance.

The main problem with it that we have run into is that if there are active transactions in the database, it can't find a "scale point". So when our application gets hit with thousands of users at a time and they are all generating database transactions, it can't scale up.

It's definitely been good for us in development though, and I would highly recommend it for that.

From a cost perspective, when I last checked, it was quite a bit more expensive to go serverless unless you have very intermittent demand or have very spikey and unpredictable traffic.