Matchmaking R.I.P

Just played a match before, but god bless we had afk and we remade this game. But in after game lobby I noticed something "intresting". My team: 1 ppl - 51 won rankeds 2 ppl - 101 3 - 320 4 - 98 5 (me) - 102 (fbm) =672 won games Opponent team: 1 - 321 2 - 154 3 - 104 4 - 536 5 - 178 =1293 won games (2x more)

I checked also their playing role and champions (champions which were played in this game) My team in this game- 1 lv7 champ (me) and 1 lv6 champ. No mains etc. Oponnent team - Otp Ashe 1kk points with 1000+games on this champion and main support with over 500+ rankeds played at this role. Ok ok, I can understand my team isn't so well, cuz I'm not also (mmr etc.), but why opponent team isn't on equal lvl to my team? I dont think rankeds are created for totally rekt other team, but for balanced game. Right? Oh, and I'm saying about elo hell. I know u don't give a shi... about this funny league, because this works better on higher leagues (I think from plat), but there are still some players who cares. Like me. So I just want ask u how oponnents matching works, cuz im confused now.