Ranking up as Pos 5. Legit?

Hi. I mostly play pos 4/5, i prefer it to other roles. I play with some friends who are usually not very concentrated (texting while playing, checking TikTok when they're dead, taking calls while we play, having dinner at the same time, etc).

This sometimes gets me very frustrated as I try to be 100% focused on the game to win and increase MMR. I'm only 2K MMR

Due to this, I decided to rank up alone in solo queue, and it has been very good, I climbed up 250 MMR this weekend. I spoke to my friends about it and they said it's nothing as I play support, so I always get carried, like it means nothing to win as a support.

What do you think? I consider there isn't a position where you don't have to make a real effort to win, but these guys put it like "You're doing it the easy way". What is your opinion?

EDIT: thank you all for your comments and support (no pun intended) words. I appreciate them all!