12 - 30 arena ranked

Hello goodnight. I'm here for the 34th time trying to understand how the ranked arena works in apex legends. why do my friends start MD10 with me i reach d2 and start gaining 12 points, and they have 108 points in the same place, with the same MMR, in the same team, with the same win-rate. Why do I take 12 points, and they take 108 points in the same place???? my MMR 80% theirs is the same and i get 12 points while they 108 ????????????????. because I lose 30 points in any match, regardless if the enemy is predator or bronze is -30 in all matches. how do you go up, winning 12 and losing 30?? even before reaching the master/predator that was already achieved by me, being wronged by the game. earning 12 points since diamond 4 needing to play 14 hours a day, while some players come in and play 5 games 108x5=540 I needed all day to earn this for only earning 12. PLEASE HELP ME!!!