TLDR: too many smurfs, throwers and people who dont know how to play the game. riot matchmaking sucks.
allat warning⚠️
I've only played a handful of competitive shooter games (fortnite, overwatch, r6 siege) yet Valorant seems to have the most abundance of throwers/smurfs out of all of them. I'd attribute it partly to new accounts being so easy to make. I, myself, have four total accounts with competitive unlocked (including my main account) that I leveled up completely by myself and played competitive on at some point in time. Often times, I'll play on one when I'm in an inferior condition (sick, lagging, etc) and riot needs to stop people like me as it's not fair to teammates. Competitive is so easy to unlock that making another account is even recommended by some people as an alternative account can reduce the nerves of losing games.
Smurfing gets very diluted as you reach higher ranks and it's becomes less noticeable since there's less skill gaps between ranks. As well as some outlier star players appearing who are simply in the wrong rank. Smurfing can also be outplayed sometimes by a smart group, as it's merely one guy. In contrast, smurfing can be very hard to combat if it's a duo or trio of smurfs, nearly impossible. Though perhaps Valorant seems more populated with smurfs because it's easier to see the impact of a single person, while in a game like Overwatch they'd probably have to play a specific agent like Widowmaker or Tracer. I don't understand why smurfing is not being taken care of more aggressively by Riot. Other games have speculations of mechanisms in place to make your earlier lobbies easier so you have a higher chance of sticking to the game, yet Riot would rather your earlier lobbies be the hardest you'll ever have during your time playing Valorant.
I'd argue strongly that having a teammate that is throwing is worse than the opponents team having a smurf. There is still an opening to outplay a single smurf player while a throwing teammate, if not just not playing, could be actively harming your team. I recall there was a time when I was in gold and I was duo-queuing and we had some five? straight games in a row where one of our teammates was AFK. It was ridiculous. There's also often dumb conflicts that happen between my goofballs of teammates that causes one of them to start throwing, even if this player is on their main account. Another time, I foolishly queued during daytime hours on a break day and a younger fella was in my team and he was tossing shit at our teammates but when they spoke back he had left the game, despite our team having the lead and on a clear path to win the game.
Something that has yet to be mentioned; players who have just reached level 20 or have recently (I'd say 40-50 is still recent) just aren't going to have the same level of gamesense that my level 800 diamond enemies are going to have (obviously). Why should my elo be sacrificed so the game knows this guy doesn't belong in my lobby? On the other hand, I've also come to realize that people who are lower level are usually on secondary accounts and not simply new to the game. I've had a couple games where one of my teammates was not EVEN level 20, they were lower. Their crosshair was sweeping the grounds, 700ms reaction time, and we had to explain to them, like a child, how we needed them to use their ultimate ability to help us win the round. I don't know who's idea it was to let players who made their account before the level requirement, completely ignore it. These accounts have not even played enough games to reach level 20 and the games they had played, were so fucking long ago!!!!