No idea where I could've better asked this question, but how does the game handle stealth vs shooting/killing enemies? Do you lose out on a lot of experience if you don't have combat with the enemies, and just stealth your way to an objective? Or is it like Witcher 3, and the bulk of experience is awarded on quest completion rather than killing enemies?

Afaict, you get the same XP for a non-lethal takedown as you do for a kill. Of course not every enemy can be subdued that way.

As far as doing entire missions in stealth, I doubt you lose out on much XP. Besides, XP doesn't seem to be an issue anyways with so many ways to earn it.

First thing to keep in mind is XP is used very differently in Cyberpunk 2077.

1. General XP is awarded based on missions to give you ability and skill points.
2. Street Creed XP is earned based on how you play in an out of Gigs.
3. Finally You earn XP for the skills based on your use of each skill in/out of combat.

Basically three different XP charts so it's different then most RPGs.

You get more street creed xp for kills than for nonleathal.
Test it.
KO a trashmob (not pedestrian) then pause a few secs till all reports pass.
Then kill it. You'll notice Street Cred goes more up.

This does not mean you should kill everyone! There are tons of targets you want to spare.
Almost all sidequests, not just gigs, give street creed XP when done. And also each car/bike you bought adds some.
That's why my SC level is skyhigh and my normal character level is just half of it. ;)
And through shards.
These shards upon collecting add XP to a skill. It's written which one.
Note also that shards that give +1 perk also exist. You get a perk point to spend.
Where to find those? I looted quite a few of 'em in sidequests. ;)
So don't just reviewer fastrun the game. Turn every stone, loot everything! :D