Gameplay posts don't have evidence to back themselves up
Just take a look into any post getting upvoted right now and you'll see that they'll make a random claim, then give nothing to back it up. Literally, we have people saying Electrocute is overpowered yet haven't provided any evidence showing that Electrocute is a strong rune right now that needs nerfs. Example of a use of evidence:
I think the balance team is bad at their job, potentially biased, and unfit for their job. I can provide evidence for that. Irelia was nerfed because her mid lane was strong, but the nerfs only affected her top lane. These changes were pushed by Ricklessabandon, who hasn't played the game in 4 years. Supports are overpowered right now and are why it is so effective to gold funnel, but they aren't nerfed for reason. Coincidentally, Meddler is a support main. (Yeah, he's not an ADC main like the boards were circlejerking awhile ago.) Reav3 and Wav3Break barely play the game. These are reasons, but not limited to themselves, why I think the balance team isn't fit for their job. A counterexample though is Riot Blautoise does play the game often. (They balance the game, so their status is as a public entity like a streamer, who do get frequently shit on by the community.)
I made a claim and gave reasons and evidence to back it up. A lot of gameplay posts are either empty or just have some randomly rambling that doesn't give any evidence to back up the claim they make. The lack of evidence is part of the reason no one takes the gameplay board seriously.