alt Hacker NewsI generally limit Oracle to where you are in a position to have a dedicated team to the design, deployment and management of just database operations. I'm not really a fan of Oracle in general, but if you're in a position to spend upwards of $1m/yr or more for dedicated db staff, then it's probably worth considering.
Even then, PostgreSQL and even MS-SQL are often decent alternatives for most use cases.
That was true years ago but these days there's the autonomous database offering, where DB operations are almost all automated. You can rent them in the cloud and you just get the connection strings/wallet and go. Examples of stuff it automates: backups, scaling up/down, (as mentioned) adding indexes automatically, query plan A/B testing to catch bad replans, you can pin plans if you need to, rolling upgrades without downtime, automated application of security patches (if you want that), etc.
So yeah running a relational DB used to be quite high effort but it got a lot better over time.