It is NOT down to DM adjudication whether you can hide or not. If you think it is, you not playing 5e. Sorry but you are just completely wrong about that. The RAW says you CAN DO the HIDE action; as long as you have something to hide behind. This is RAI as well, as you can easily confirm.
Can a rogue hide in such a way that opponents cannot see nor hear them on a regular basis? Assuming that the environment is one that supports it by having appropriate cover, of course a rogue can attempt a stealth check.
That does not mean the enemies forget the rogue is there. That does not mean that the rogue can "peak out and attack" while remaining unseen. Line of sight is usually a two way street. In most cases if the rogue can see their target, the target is also capable of seeing the rogue.
I'm pretty generous when it comes to stealth in combat, but tossing around meaningless phrases like "RAW" to justify how you run the game doesn't mean anything.
How stealth is handled is going to vary from DM to DM.