I am currently playing with a new account flex. It isnt the thing that they make bad desicions, since that is to be expected. The real problem is that they give up way to early.
It was min 13, quite even score (11/13), enemy rengar got a triple kill. Now midlane and jungler are starting to write "omg game is over" "ff" and dont concentrate anymore. they now overextend as hell and get catched, because the game is already "over".
That happened to me quite often these days while playing in this elo. We are loosing not because there happened a misplay once, we loose because they are tilted and think the game is already lost.
TL;DR: Don't give up just because some few misplays happen. Only if your team lack cc and EVERY member of the enemy team outscales the laning partner.
I really dont care if I lose a game because the team didnt worked well, but loosing because of team members who start playing into the loose, makes me tilt.
Have a nice evening.
_ps.: i know, not every low elo player does this, but it happened to me quite often in the past_