I agree that it does take away from the immersion. But IMHO there are two different things here, at least in RDR2. The HUD is by far the biggest problem in the game. But it can be disabled (on PS4, hold DOWN arrow and then you get the option to switch it off). Doing this was the single best thing I ever did in RDR2 (well, apart from replacing the in-game music with Bob Dylan's soundtrack to Sam Peckinpah's Pat Garrett. Seriously, try it.. :-) ) . The downside is you often find yourself getting battered by surprise gangs of bounty hunters.
I feel the map is not so much of an issue, though as you suggest, a series of proper maps in your satchel, similar to the treasure maps, and obtainable in stores, etc. would have been amazing.
For anyone replaying single player, switching off the weapons reticle and the HUD makes the game unbelievably immense. That for me was worth the 5x increase in dying!
Yeah, that's sadly true—shame you can't do the missions without the map/hud, some sort of paper trail would have been much more atmospheric... In general, I'd have liked to have seen a bit more balance between the character-driven—but extremely controlled—missions and the free roaming. I replay a lot (still my overall fave game), but mostly just free roam. For me, switching off the HUD really opened things up, slowed me down, made me aware of sounds, etc.