This has happened COUNTLESS times to me in my games. Just because something is off-meta does NOT MEAN THAT IT WILL NOT WORK. Sure, if it doesn't work, it can be frustrating, but you're setting yourself up for failure when someone shows an off-meta pick in champ select and you immediately think "Oh, this isn't meta, we lost because of this guy". That attitude is what's going to cost you the game.
Every champ can win a game in any role if you play them and around them properly. For example, in one of my promo games out of Bronze 5 (kms), I had to play against a Volibear - Fiddlesticks bot lane. I was mid, so I assumed that they would get crushed by our bot lane and we would win the game easily since they didn't have an ADC. Guess what happened? Our bot lane was 0-11 by 10 minutes. They both got strong as fuck, then proceeded to roam around and dominate everyone in sight. We lost so badly, all due to Fiddlesticks and Volibear in bot lane, and since no one had ever played against a team comp like that, we didn't know how to stop it. That's one of the advantages of off-meta picks - the surprise factor. If you understand what you need to do AS the off-meta guy, and do it successfully, the blind sheep on the enemy team will often times not know how to play against it, especially in low elo like me. This leads to an easier win and a great learning experience for everyone.
Yes, off-meta picks can also be confusing to play WITH, and cause frustration when they aren't doing very well, but do not go into the game saying "we're already fucked, we have a Soraka mid, we lost gg". This spreads toxicity and salt, which is the #1 reason why games are lost or thrown. NOT because someone wanted to go off-meta.
Have a great day everyone.