Before I say my suggestion, I know that having a mastery as a champion doesn't necessarily make you 'good' at that champion. So if your immediate reaction to my suggestion is commenting "This is a stupid idea because mastery means nothing to skill", then just leave my post alone please.
I'm in Silver 3.
I don't think I'm a fantastic player and I don't think that my highest mastery (m7 w/ 80k points on Talon) makes me a fantastic Talon player or even a better player at all, I love the mastery system and in my humble opinion, it means nothing to the actual game. I think of Masteries as like a fun side mission for personal satisfaction, I think earning higher masteries and collecting higher masteries is a fun side goal away from the main goal of every league player (Getting better at the game). Which is why I think that Mastery 8, 9, and 10 should be added to the game with some cool graphics and border designs, not to brag to other players that I'm the best, but as a continuation side goal for myself.
I've seen some other posts like this that suggest making the next levels in masteries be based off champion points instead of pure S+ ranks (Ex. m8 = 250k points, m9 = 500k points, m10 = 1mil points). Personally, I agree with that post (link to that post at the end), I think that spending enough time on a champion to the point where you have anywhere from 250k Points to a Million points should be rewarded, not with random keys, emotes, or skins, but with a very simple new Mastery.
Obviously not everyone is going to agree for their own reasons, but if you're just going to trash on my idea and opinions because "Mastery has nothing to do with skill" then please just ignore and leave my post, I'll reply to constructive criticism but not hate, Thank you.
Link to the requirement post - https://boards.euw.leagueoflegends.com/en/c/community-creations-en/AhdOXWzT-champion-mastery-8-9