LP Loss for having Rage Quitters on the team

I have had multiple people do things that throw games, causing me to lose lp. However rage quits and afks should not take almost 20 or more (being in higher elo than I currently) lp from anyone.

Picture this:

15 minutes into a ranked game, neither team has gotten any towers yet, but are pretty even with each other. The jungler who has been doing well decides to roam top and assist top lane. Top lane gets the kill, jungle does not. They rage quit. Now its 4v5, enemy team's jungler () has more ground against your team due to high damage, one tank on your team and the others being squishy, and being invisible almost anywhere except for around towers. The second your team gets a chance to take advantage due to the opposing team being out of position, their jungler comes in and completely wipes everyone out, including the tank. Their jungler, being 3 levels ahead of your team and part of their team, has more gold, more farm, more items, and complete control over all jungles. 25 minutes in, game is done. You get into post game lobby, there is 16 lp deducted from your lp for losing the game. All because of a rage quitting teammate, that being the jungler, which gave the enemy team a huge bonus for gold and control over objectives.

My question is this: Why should people be losing that much or more lp for playing a game that turns into a 4v5 or worse a 3v5, 2v5, 1v5 situation, all because of someone who leaves?

Your team loses a teammate, while the enemy team now has advantage or has a bigger chance to win if they're behind. That makes it unfair to those who have sat through and played an entire game only to have that happen and now have to lose a ton of lp because of one person leaving.

There should be either less lp deducted from games with rage quits or as one rioter that I have spoke with suggested a lp loss prevention system since this can occur repeatedly. Someone could wind up back to back games with one or more teammates leaving, and still lose lp for them leaving.

Side note: a kind person had recommended to copy and paste to this forum page instead of Discuss the Boards and pointed out some of the common issues with balancing this.

My Thoughts:

Emergencies Happen: Most people will say that there's an emergency or something going on. Personally I have had to leave a normal game or two due to medical reasons, this could very well happen to anyone in ranked. This falls with the internet loss topic where I would say no one had control. Not my call on this.

Power/Internet Loss: Cannot really blame the player for losing their internet during a ranked game. They don't have complete control over electricity during storms or road work involving cable and internet lines. Players tend to stand still whenever they lose power/internet which is a dead giveaway for anyone.

Harassment to Save LP: This could be solved with the rule of "Punish everyone" rule. Someone isn't doing well, they leave due to harassment, the teammates harassing definitely deserve to lose that much for being toxic. The player has an option of muting others and continue playing.

Duos int to help their buddy: If they're playing together, the system should show that they were in a party before the match started. How this hasn't been addressed till now kind of shocks me knowing that there has been duos in game I've played who either left or intentionally ruined the game for my team. These deserve the most lp loss on the team.

Taking one for the team (odd topic the kind person recommended): They informed me that Guild Wars 2 has something similar to this where if someone is not doing well on their team, they could tell others that "I'm out" and leave or something on the lines of that. It's a different game for 1, 2 just because someone isn't doing well doesn't mean they should leave the game. I had a who wasn't doing well (farming wise and died alot) but still was useful for a few reasons: Taking Towers, Split pushing, and Bait in Teamfights. As cruel as it sounds for the Bait part, that led our team to dominate their team in a fight simply because they want to focus the damage dealer. She could also push towers and take objectives with her E and Q. If not taking objectives, she would also push lanes while we had the enemy team in a single lane. Just because someone is not doing well doesn't mean they have to leave. There are other uses for them.

They have systems that can register duos, people who leave, take stats, they could even see when people leave a game and read the logs. But still want to implement the "Punish Everyone Rule" for a single person who decides to leave because of not getting a kill or a gank.