Should lvl 30 accounts still be able to play ranked?

I recently played a ranked game with a player who had just hit lvl 30 and was doing his placement matches. He hovers Vayne, but the other team bans her. He proceeds to lock in Ezreal and says in chat "first time Ezreal lmao." At this point I was kinda suspicious but I didn't dodge because I figured I should give him a chance to play the game competitively. Once we got into game, I realized that he took Press the Attack and not Kleptomancy. A poor choice, but not trolling so I just shrug it off and play the game. Now sadly, he starts dying over and over to the enemy botlane. The game is practically lost and I can't do anything about it as a midlaner. We lose, and my team tells him that he should practice in normals before playing ranked or he will ruin other people's games.

The issue I have with this is not that I lost a game, or that the Ezreal played horribly. My problem is that over the course of two years, Riot has reduced the amount of XP needed to level up to level 30. At the beginning of Season 6, they cut the amount you would need in half. Then again, I believe during Season 7, they cut it in half again. This means that players don't have the "Trial by Fire" aspect that older players had to go through as they progressively got better. Instead of having to clock hundreds of hours on the game in order to unlock Ranked, these new players can jump in while they are still quite unready.

If you have played since season 5 or before, imagine this: You queue up for a ranked game, and when the queue pops, you type "mid" in chat a fast as you can. Sadly, another player beat you to it, so you take jungle instead. As champ select goes on, this player starts talking about how they just started playing Ranked, and when you check their OP.GG, you find out that they are actually only level 20 (on the old system). How would you feel? Most of the game sense and champion knowledge you learn comes between levels 20 and 30 - after you have picked up the basic movement and spell casting. This is what is happening now. Players who have played only 1/4 of the time that you had to play in order to get to level 30 are being placed in games with you and are being expected to play as well as you.

TL;DR: Riot should change the leveling system or alter the minimum level requirement to play ranked so that new players who have not developed the skills they need to aren't placed into games with players who have played for several hundred to a thousand hours.