How League is losing players

So not long time ago I met one player in rankeds. It was his first ranked game ever. I'm playing since S2, so I was happy to see a new player and help him. So I played with him like 3-4 rankeds, can't say he was best player, but he was trying his best listening to all advice. However we lost all our games. He showed me his champions pool and asked if Jax worth to main? I said "no" - Jax isn't in his best position for long time. But to cheer him after lose streak I called him to play normal. He get toplane and picked Jax. His enemy was Yasuo.

And Yasuo started to killing my friend non-stop. Just farming him like a minion. I tried to help him, but Yasuo was outplaying us like a god. Like we are all newbies - this slippery monster always was dashing or having shield or knocking us up. He died only when there were 4 of us already. But at this point my friend was 1-9, Yasuo 13-3, so we decided to surrender. My team reported Jax for feeding. I was trying to cheer my friend after lose streak in rankeds, but all he get is shamful lose and reports from teammates. As result my friends said that he didn't have any good game in last 4 days and probably will uninstall LoL.

Now pls tell me isn't League is goind really too hardcore? Yasuo was Silver 3. I can't even then image what Diamond Yasuo can do. Plus I can't get where are this MMR ELO mechanics that have to give my friend enemies of his level or at least less hard, because he's getting lose after lose. Plus this community - all what people can do here is just blame each other. I guess in last years game became too stressful and too dependant on FOTM picks, and this all this makes LoL much less fun than if should be.

Help newbies, guys.