We have the systems, why we don't use it? / Competitive mode

I was thinking time ago: Why the competitive is like it is?
Look, I’ll explain myself: I understand perfectly why the system is like it is, a lost implies that you’re actually worse than what the game put you against, which on paper would be on average people of your same current skill rating, and therefore you’re below your current numbers, so the games takes points away of you to adjust your skill rating to something closer to your actual skill level. And that’s the keyword here: Adjust. It never changes, it just gets closer to the actual number used to represent your skill level.
But this system has several flaws, one in particular I’d like to adress on this post: It discourages the players from keep playing.
Let’s suppose that you got crushed to death on a competitive match, you did as much as you could and actually had pretty good stats, it’s jsut that the enemy team was above you on skill level, despite the fact that the skill rating was extremely similar. Seeing the skill rating go down, on this culture that embraces competitivity, is a pain to the heart, it discourages anybody to keep playing, or just playing to recover those points, moved mainly by frustration rather than competitivity, he’s not looking for more, he’s just looking what he unfairly got less.
But then we always reach the same question: How do we fix it, if everything we can count on are a bunch of algorithms? There is no couch or analyzer or any human mind able to comprehend the mechanical understanding, to tell whether we improved or not on real time on every match we play.
But… We already have a system like that. The system is already capable of placing ourselves on a certain rank based merely on our performance during 10 plays: When we first get to the game, it has no reference to play us, so he has to work only with our raw performance, there is also this system that can tell if you underperformed or overperformed, and, combined with the SR difference, will take you or give you more or less points based on what’s needed. Why don’t we improve that system and make it the default system for the entire competitive mode? It doesn’t matter if we win or we lose, and on a game that depends so much on teamplay, there are MANY, MANY, MANY variables that can give us a victory or a defeat, and many times the victory can feel underwhelming or undeserved, and the defeat can feel frustrating or unfair, both disencouraging the player from jumping again to ranked.
On this system, you can lose or win, it doens’t matter, because you still can win points, and the system, once again, adjusts your skill rating based on your updated performance rather than the raw result of the match. This also makes the defeat way less frustrating and bitter, because you don’t have the idea that you got crushed to death, and if wasn’t enough, now you will lose points. On this system, you can even be excited after a defeat to see if you performed well enough or not.
We have the systems, why don’t use it to make the situation better for everyone?