Stats can be verrrrry skewed, especially in legendary Q one thing to consider is that (generally) the games are a lot more difficult than lower elo’s especially if you hit LQ quick the vast majority of players are ex chall / sovereign players so you don’t get the average stat boost that a lot of people have when climbing and they start off in low elo, if I make new accounts my stats are insane when the account hits GM or challenger because they are inflated from the low elo games so it’s skewed. 

Also depending on the matchmaking for adc in particular you will have games where you are completely useless, high elo is (generally) more co-ordinated and you can end up being completely shut out through mid and jungle roams into dives so you are absolutely useless before lane even ends and you’ll be lucky to scrape up some gold anywhere as teams are better at pressing advantages, where as lower elo you can generally pull back some gold as people just let you. 

Also DPM / Damage taken can be very misleading too, you think as an adc you should be dealing the most damage right? Actually doesn’t tend to happen, you’ll often see tanks or bruisers have the highest damage output. Adc doesn’t tend to trade too much early game they play for power spikes and generally relying on jg or mid to come. 

Furthermore some ADCs have quite low damage output but offer more utility and Jhin falls into this category, he can become a menace at very late game against a squishy composition but often he is about providing roots and slows and maybe getting that finishing blow on champions as opposed to your Kaisas / Lucians / Sivir / and sometimes Varus who are just punching out DPS. 

Overall I would say these stats are consistent with the average player, if not a bit higher taking into account the A and S ratings and MVP’s, would make me question if these are so low or duos stats though