It's not about how much time you spend on the game.... but how you spend it.
I am gonna use myself for example. I am pretty bad at csgo..... and kinda of good in dota ( was about 6k when the top MMR was 8)k, WHile i play dota games, i clearly can see myself improving in every game, trying to fix my mistakes... and when it comes to FPS games, i can play as many matches as i want, and i am still a BOT.... and that's because i dont know the workflow to improve. So even if i play 10 hours of DM everyday i dont think i am gonna improve that much. The guys on your friend list are just playing games, and spamming games on mirage wont make them good at all.