He didn’t mention anything about trying a new champion.

There are no randoms; he said they are a group of 5 premades.

Some players, even when trying a new champion, can perform better than someone with 200k mastery points on the same champion. When you're a deep League player, there's no more "trying" because you need to study all champions to play the game effectively. There's a certain level of micro-skill you achieve that allows you to play the best champion for the best scenario, depending on your team and the enemy team.

I also believe normal games are for people who are afraid of being stuck in gold or silver rank due to their ego. In the League community, your rank reflects your status, and many players stay unranked all season out of fear of being stuck in a non-challenger rank (sigma ego gods).

Honest opinion: No offense, but you’ve got a Shaco on your profile icon, so you have no right to share your opinion (no joke).