9.7K Priemer Rating but I am trash at the game. Does anyone know why?

[Zaconator Illusions]

Hey guys, like the title suggests I am currently 9,721 ELO and my friends who I 5 queue with are all ranging from 4.8K to 7.3K. I very seldom solo queue. I am leagues above them in ELO however, I am consistently the bottom fragger of every singular game. Can anyone give me a few reasons as to why this is? The only explanation I can have is while I only play with them, they play amongst themselves and solo queue more frequently than I, and I am better at getting win streaks instead of W/L/W/L. Another theory is I am my playgroups designated bomb carrier and I am constantly playing objective planting the bomb.
If everyone can elucidate any reasoning as to why I am such a higher rank than my friends I would appreciate it!