I'm aware that games built with a goal of being easily modded often store data in plain text documents, such as Rimworld, but how often is this actually the case in games development? I can't see why an entire database system would be implemented just to read a few saved variables, but at the same time, if it's more efficient or built into the engine there's likely no reason not to use it.

How is data stored in typical game projects?

Typically games built with a goal of being easily modded often store data in plain text documents, such as Rimworld. I can't see why an entire database system would be implemented just to read a few saved variables in other games? Sure if it's more efficient or built into the engine there's likely no reason not to use it.