Hence the word partly…
But just because you got better as a player doesn’t automatically mean you climb…others are also getting better…and ranks are based on everyone…(Everyone goes through what you described btw…it cancels out on the long run…unless you really believe you’re more unfortunate than others)
I’ll repeat…you can’t say rank X means the top X% of players if you just throw everyone in there…it’s a tier list for a reason