Do you gain less ranking the higher rank you are?

I’m confused on how TRN ranking is calculated…

If I use my last game for example -

I placed 2nd with 9 elims but gained 10 rank score(4557 to 4567)
On the TRN Rating & You page it says -

"If you win, and you get >7 kills, you receive 5% of (5000-currentScore).
If you win, and you get less than 7 kills, you will get 4% of (5000-currentScore).

2nd and 3rd tier work the same way. We expect you to get 4 and 3 kills at least respectively. If you do, you will get 2.5% and 1%. Getting your required kills grants you an additional 1% on both."

Shouldnt I have gone up 2.5%? (4557 - 4657)

Do you gain less rank points the higher rank you are?
I’m so confused…

Yes. 5000-4557 is 443, so 5% of 443(22.15) is more than 5% of your next 5000-4567 which is 433(21.65 at 5%).