So did you send your database logs to a centralized logging system? Did you set up roles and keys to access those systems? Are your roles integrated with the rest of your permissions system? Do you have a perf dashboard where you can see the real-time usage of your DBs? Have you already rehearsed updating your database version?

The thing is that it's totally possible that you learned everything needed to set up the cluster, in my experience most database systems that aren't set up by a professional DBA will sooner or later hit a configuration or maintenance snag. Once that happens, you're pretty much totally on your own and for critical systems that downtime is going to cost you more than the costs of your infra.

So you either need to have a DBA on retainer if you're serious about data integrity, or you pay management costs which means your system was set by literally the most expert people on the planet in the area.

If you're running a cluster where performance is the highest priority and downtime and maintenance isn't a huge issue because you have a nice decent maintenance window and enough dev cycles to spend on staying up to date, for sure, go for it.

But in my experience, if you care more about a system staying up, good managed infra is so much more reliable that it's not even a question.