Quote from DorkForge >>

That's not an exception or clause in the rules, that's a feat giving you a specific benefit because you've mastered a specific type of weapon. 

It doesn't really address what I was talking about and in a game where your chance to actually get feats (if they're allowed)its far from ideal.

 Ranged Attacks in Close Combat

Aiming a ranged attack is more difficult when a foe is next to you. When you make a ranged attack with a weapon, a spell, or some other means, you have disadvantage on the attack roll if you are within 5 feet of a hostile creature who can see you and who isn't incapacitated. 

If you've got a way to incapacitate them, you're good. Switching to melee weapons or melee spell attacks is another way, and you don't even need to stow your bow if it's a one hand melee weapon (or potentially a spell).

Prone

A prone creature's only movement option is to crawl, unless it stands up and thereby ends the condition.

The creature has disadvantage on attack rolls.

An attack roll against the creature has advantage if the attacker is within 5 feet of the creature. Otherwise, the attack roll has disadvantage.

Prone grants advantage within 5 ft and doesn't exclude ranged weapons. This cancels out the disadvantage from ranged within 5 ft. 

I know that 5e is not a rules heavy-edition or system, nor do I want it to be. Neither are any of the things you listed the same kind of thing at all, it's not simulationist to say shooting at the guy lying on his belly in front of you should be easier than shooting that guy 30 feet away. Maybe there was a misunderstanding in my posts at some point, but hopefully I've clarified what I'd rather the rules reflect.

Okay... Thank you? I understand all of the rules and conditions involved. I know there's many ways to cancel out disadvantage and gain advantage. I was talking about the rules, and mentioned what I would like them to show, apologies if at some point I conveyed there was no way to gain advantage on a prone creature within 5ft using a ranged weapon.

Quote from Chicken_Champ >>

Yeah that always gets me too, I always remember the rule being "prone gives disadvantage to ranged attacks!" but in reality it's "prone gives disadvantage to attacks beyond 5 feet from the creature." So with Crossbow Expert you have no disadvantage for making a ranged attack in melee, and are just left having advantage against a prone target that you are standing next to. And without it, you're making a normal attack, not one with disadvantage. 

 Note to self: drop prone and crawl up to the polearm master.