Serious Question About Friendship

So I've had a gaming friend for at least 1+ year now and during our gaming time we played many games CS:GO being the main game. Now as we started at silver 1 and climbed up the ranks we (or should I say me) have hit a dead stop in the ranks (MGE, my friend being MG2)

Now my friend I believe and I can see from the scoreboard is not as good as me. Almost 9 times out of 10 bottom fraggin and losing 1v1's 90% of the time. Whilst I'm top fragging and carrying. Most of the times carrying isn't enough to win...

So I want to say that I don't want to play with him because he isn't as good as me/I want to rank up... But I can't tell him straight up he has be loyal to me... So how do I tell him?