Champion Mastery Problems and Discussion

I have noticed recently that the entire system of "Champion Mastery" is quite flawed. The biggest issue is that the "mastery" aspect is primarily based on winning, which does not necessarily equate to mastery of a champion, as one could get carried and win or one could lose but still have performed very well. For example, I recently played a game where I went 13 and 8 on Lee Sin, with a decent amount of assists, but my team lost. I still received an "A+" letter rank at the end of the game, but I still acquired the same 200 champion mastery points that all of my team did, even though I know some members did not do quite as well as I did. I think that the current system is flawed in this way. I made a thread yesterday about the same topic, and I have also read up about the issue with a decent amount of length, and I have found some good ideas suggested by forum users as well as external posts. Some of them include:

A sort of decay system, so that one can not simply get carried to level 5 and then stop, and also as a sort of personal ranking as a way to see how good one is on a champion (this would also encompass a possible edit to make champion mastery levels unlimited, as there are some players with over 100.000 points on champions but they are still stuck at level 5, which is not fair)

Make the points gained at the end of a game (regardless of win or loss) based off of the letter rank received. Many have pointed out that the letter rank does not actually carry much meaning as the primary brunt of mastery points are rewarded based on a win or loss. In this idea, it is also noted that perhaps a small boost (maybe 300 points or so) will be awarded for winning, but the majority of points would come from the letter rank instead of simply winning or losing, to compensate for those who might get "A" ranks and still lose and to give less of a major reward to those who get "D" ranks and still win.

There were many other ideas submitted and they were all reasonable, and I would love to hear anything else anyone might have towards the issue or any other general comments about the Champion Mastery system, such as other possible fixes or a reward system or really anything, any input is much appreciated!

Thanks all, and I know it seems like a very trivial thing to discuss but I don't want to think I'm the only one who sees the flaws in the system, since it is obvious that the "Champion Mastery" system is not actually based on mastery of champions.