losing LP in Ranked games because of an afker

I think that there needs to be a better system in rank when you have an afk or someone is not able to play the game and it turns into a 4v5 like maybe if its an afk from the start only he loses the lp and the other team gets half of what they would have earned since the 4 people was at a huge disadvantage or something along the lines to reduce you being taken away a lot of LP when its not your fault for him being afk

this got me thinking because I recently played a game where we had an afk person who came back at around 40 minutes but by that time our nexus was open he was lvl 1 and we could only defend till they kept stacking dragons and barons till we couldn't do anything but defend till our inhibs respawned, but unfortunately when we tried to push even a little, an adc takes 10 sec to take our nexus and we lost that easy, while also having 17 Lp taken away because I couldn't win a 4v5

there needs to be a huge change for the Lp system when something like an afk happens because that's why many people hate ranked I think this needs to be seriously discussed and a change needs to happen