Just a brief STO thing..
Kaos, if you wanted you could skip Space or Ground combat completely.
It helps to be in a big Fleet, too. The thing with Fleets, as far as I can tell with my limited experience with them, is if you are in a low level Fleet - that is good because I think it's way easier to get Fleet Credits as the Fleet levels its various assets. (So a newb Fleet is good for newb toons?) I'm in a Fleet where everything seems to be about maxed out and it seems expensive to get Fleet Credits as compared to how it was in my brief time in a low level Fleet. But. There is plenty to do at the various Fleet assets in a high level Fleet - places like the Fleet Starbase, Spire, Dilithium Mines, etc. There's above average shopping, highly rewarding mishes that don't require any combat (Duty Officer, R&D..), all the conveniences like access to the Exchange, mail..
How I leveled Xev, was, I did PWE queues for Rep and XP and *some* highish end newbish loot - this is what I did/do the most of as far as combat goes. Then comes Patrol mishes (there are Ground Or Space ones), and those random Alerts, which, I think are the only thing I used to do (I very rarely run them anymore) that is all Space (I think there are no random Red Alert ground queues?)... When I wasn't doing that I was running around doing Fleet stuff, R&D stuff, Duty Officer stuff, selling and buying stuff....
This is one thing I really like about STO. It's kinda open ended. It can be played to endgame more than one way, and, in very different ways. You're kinda left to figure out how You want to get there. Its Build system is pretty strong, too. Meaning, I can (hope to..!) make fairly sophisticated and varied Builds.