Why does very single possible opening need a name?

Ok so this needs some explaining. Im very much a chess casual, but whenever I see other people talk about the game they often have names for every single possible opening. Meanwhile, I’m there thinking to myself “why though?” I get naming the more popular ones, but every single possible opening imaginable? Does me moving a pawn one tile in front of a Rook really need a name? You don’t see Tekken players giving a name to every single combo for every character, or Overwatch players naming every single possible team composition. Am I missing something or what?

I think what you're missing is that chess isn't a videogame.

If you want to search for and study an opening, of course it should have a name. Would you rather put the notations instead to look it up?

The name is just shorthand for easy reference

e.g. instead of saying "1 e4 c5 2 Nf3 d6 3 d4 cxd4 4 Nxd4 Nf6 5 Nc3 a6" you just say "Najdorf"

I understand that as a beginner it can seem like a lot, and that can be confusing, but I think your points aren't really correct at all. To start with, not every opening has a name. Sure, there's probably a name for every first move, since that is very easy to do, but when it comes to actual openings, only the most famous or common lines have names after the first 3 moves. This is used as shorthand to make them easier to learn, rather than you having to memorise and repeat the whole move order of the poisoned pawn Sicilian, which is well over 10 moves. 

Secondly, your two examples are actually pretty terrible. While not every combo in Tekken is named after the player that popularised like in a much older game like chess, the combos do have names. Every character has a Bread and Butter, a Corner Carry, a Wall-Splat and and Wall-Break ender, and any number of Oki or Read setups, which is no different from learning to call things the Sicilian or the French. And in Overwatch, at least at pro level, there literally are names for the different viable comps. From Dive, to GOATS, most of the teams that are used at competitive level have names, and this is again, simply because it is easier to talk about them this way, rather than ringing off 6 characters every time you want to talk about it. 

Just because you don't know the nomenclature for a game doesn't mean it doesn't A./ exist, and B./ have a reason to. 

please delete this 

Imagine if Tekken was played for 1,500 years and the subject of over thirty thousand books.

Everything has been named, because every possible opening has been studied in depth.

Variations have names, not every move. But people need a handle, something to help them remember and categorise. A name is an easy thing to remember, attached to it are plans, ideas, themes, traps and tricks.

Chess is not a video game.

Not true.

Which part?
By "everything" I meant all the openings.

Imagine saying “I’ll play the e4 g6 opening” instead of “I’ll play the modern defense”

one is easier to say

i think they have actually, my book has got like two lines for both

Honestly, if a GM sees someone play a dubious opening, like 1. e3 or 1. a4, they don't even name the opening. They just say something like, "e3??? What is that?!?!!"

Actually the OP does have a point. 

People sometimes mistake classification for understanding. They sometimes think that just because they can say "Ah, yes... you are playing the Breyer variation of the Morphy Defense against my Spanish Opening!", that means that they UNDERSTAND what's going on on the board.

It doesn't.

Simply memorizing the names of different sequences of moves isn't chess. It's stamp collecting. 

Sorry for the ambiguity. I meant that not even close to all possible openings have been studied in depth. 

Did the OP actually say any of that though? 

Now you make me wonder why things such as the Sine Rule, Cosine Rule, Pythagorean Theorem etc existed.