Matchmaking against players

Typically I don't use the forums, I visit from time to time but I noticed that there isn't a discussion about this so here I go. Recently I've noticed that the matchmaking against players that I've gone against and others have gone against isn't very fair. I've only experienced it once, me going against a plat, but i see on social media that it has become a reoccurring thing. I've played league for a few years and i have never been up against an unfair match but in these recent months I've noticed that changing. I just wanted to try and bring it to riots attention that some matchmaking isn't fair for some people and might need to be fixed, before people start to leave.