Can we talk about how the lol system punishes entire solo queue teams with a leaver

So you're in solo queue promos and you get into a match. 7 minutes in your jungler dies in a failed gank to the top lane and your top decided to leave and they're not coming back. Now it's a 4v5 and you're almost certainly going to lose the game when it could have been an easy win. And you lose your promos. All the work you did getting there wasted by a single person. How is it fair that someone intentionally leaves the game and the 4 other teammates still have play out the game they know is a loss and lose promos/lose the same amount of lp as a 5v5? If you're gone long enough that leavebuster puts that X through the portrait and doesn't return or attempt to return there should be some sort of cushion for the other team members who did nothing wrong. Whether that can be a loss prevented, reduced lp loss or temporary increased lp gain or some other method. It seems like Riot is only focused on punishing those who do and doesn't care about how those leavers affect other people. Riot is basically the 0 fighting tolerance school and when someone in a group hits someone everyone gets punished for it. There are so many other moba type games that when someone leaves there is a cushion for the other people who didn't leave. Why won't riot implement one here?