Most players that want the party 5's solo que are casuals or dunning kruger players

Why would casuals want party 5's? They can play with all their little friends and still have it be a "competitive" environment for as long as they want and then stop playing till next weekend since they dont get anything from playing normals. Honestly dont know riots excuse for not being able to play ranked 5's besides needing enough people. IN that case add your party 5's to ranked 5's? sounds 30x better. Why dunning kruger players? because these players believe they are stuck in low elo because of teammates and believe that if they play with their friends they will get higher. Yes and no. Yes if your buddys are better than you in which case yes you will rank up higher but only slightly and you are basically elo boosted anyways since you wouldnt be able to get there without having those better players on your team. No because you will still be close to your same elo unless you are getting boosted and playing with way higher division teammates and then your rank doesn't matter and it ruins the competitiveness of the game.

for example i played on a team of 4 gold players I was the only diamond player (but was gold at the time so i didnt know how good i was)this is ranked 5's. We won 3/4 of our games because i was good enough to carry my teammates most of the time and could lead them good enough most of the time. These players as individuals were terrible and would never last a chance against the teams of diamonds/plats we played against. Why should these players benefit in a Solo que style game mode just because they could have someone like me basically do everything but play the game for them? Sure its a team game but this is SOLO que if you want an actual team game ranked 5's is already there its not hard to find others. I dont think players that are actually silver/gold level should be at a diamond ranking just because they get their with buddys and then when their buddys arent on they feed the ever loving fuck out of games and then plays normals until buddys can boost again. its just incompetent to think a party mode and a single mode with singular rankings could be put together because last time i checked a party is more that SOLO

tldr: Only benefits people who are competitive with friends when they want to be , benefits lower skilled players who can have buddys boost them,benefits boosters,benefits casuals and players with alot of good friends. Things it ruins, the competitiveness of solo que, little left meaning of solo que and skill in solo que, individual players and ladder.