No, you may never have had to switch databases, but I have worked on codebases where we've had to switch databases, and I'm sure others have to. Most likely when dealing with monoliths where you can't do a full re-write and you can't break out a separate service for various reasons. The repository pattern is your friend in these situations. An ORM should ideally be able to read/write to multiple database drivers which makes this easy by dual-writing to both databases from the repository layer.
No, you may never have had to switch databases, but I have worked on codebases where we've had to switch databases, and I'm sure others have to. Most likely when dealing with monoliths where you can't do a full re-write and you can't break out a separate service for various reasons. The repository pattern is your friend in these situations. An ORM should ideally be able to read/write to multiple database drivers which makes this easy by dual-writing to both databases from the repository layer.