Intentional Feeders and Players That Throw Games

I want some other players' opinions on something that I believe to be a major issue with playing League of Legends, especially in lower ELO. Players that get pissed, start feeding intentionally, and throw the game IN RANKED. So I was hoping to have some discussion on what players think about this, whether it's just my imagination that it's a frequent and large issue, and what players think the punishment should be.

To begin with, I've actually started doing some tallying, and on average I will have a player in a ranked game intentionally feed or lose the game one out of every five or six games (somewhere between 15%-20%). And I don't mean games where a player does poorly, or someone rages and them and they start doing bad. I'm talking about the blatant examples where a player will say "Please kill me, I'm gonna feed and throw" in all chat, or tells his team he's pissed off and is gonna throw the game. And any attempt to talk them back to sanity is then met with "Whatever, this is my smurf, idc, I'm gonna throw" or the even worse response, "I do this all the time and I've never been punished, so idc."

My opinions on this: I think this is an egregious issue. Allowing this kind of mentality to exist creates a situation where players no longer have any control over their ability to win. And from my observations is seems like the issue is widespread, and players that commit these kinds of acts aren't punished enough, if at all, by Riot. Ideally the tribunal system wouldn't have been down for the last 3 years and the community could police this, but with Riot's new automated punishment systems, that is no longer an option. But I believe that worst of all is that this is allowed to happen in ranked games where players are heavily involved in their win/loss.

I'm going to end this with my overall opinion on how I believe intentional feeding and throwing games should be handled by Riot, at least in ranked games. I personally believe that in a blatant situation where you say in chat that you're going to throw, and then you do so, it should be an immediate, first-offense punishment. I also believe that the punishment for a first offense should be an immediate and irreversible ban from ranked play for the duration of the season. They shouldn't need to be report in 5 different games by 10 different people, they shouldn't get multiple chances, and punishments should be severe. If you're going to ruin the game for other players, purposely lose games when that's the sole reason that people play League, and harm another player's ability to rank up, then you shouldn't have the right to play ranked games. If that's the mentality you take, go feed, afk, and throw in normal games, and then have even more severe punishments for repeat offenders such as a week-long ban from League, month long ban, season long, perma ban, etc.

So some questions I'm curious about from other players:

As a player, do you see this kind of behaviour? If so, in what ranked levels do you see it? Or do you mostly see it in non-ranked games?

As a player, have you ever done this kind of thing, whether on your main account or on a smurf? Have you ever been punished for it?

From your observations, does it seem like Riot is even attempting to punish these people? Do you think the punishments are too lax? Too harsh?

What affect do you think this has on the overall success of the game? Does it ruin the game and should be addressed immediately? Or is it something Riot doesn't really need to address?

Do you think that throwing a game or intentionally feeding should be a bannable offense? Should players be banned the first time that intentionally feed if there's chat-log evidence showing their intent to feed? Should players who intentionally throw ranked games be banned from ranked play?

Thank you for taking your time to read this. It's an issue that I'm very passionate about because I see it frequently, it seems to me like it's not being addressed through the punishment system, and it ruins League of Legends for other players. If there was a reason for me to stop playing the game, this would be it.