I had this experience, too. Got reported by 3 premades cause at about 25-30 minutes into the game i was stating "I can only see 2 wards on the map and they are from my upgraded trinket. Can you please ward a bit more cause we can't see the enemies coming from the sides?"
And it was a very polite question imho, no one upgraded their trinket or sightstone... i still got reported for intentional feeding with a 11/4/7 as toplaner.
I would love to have a pure SoloQ without premades or have at least an indicator in Teambuilder and Normals where i can see which people queued up together. This would remove the "we are premade i would like to sup [xy]" and make you maybe think twice for going aggressive vs someone and just mute them alltogether.
After several games this week i am in a state where i don't want to chat anymore in Normals and just keep my mouth shut often which i think is morally questionable when someone is being accused falsely for "feeding, not ganking, not warding, KSing in teamfights, ..."
This means that a mixed SoloQ and PremadeQ will not reward standing in for players who get accused ingame but instead will make me just think "oh good they blame the jungler. At least it's not me"