I dont know whether this point is significant , think of aronian being a top-gm and telling everybody whether being asked or not that he doesnt no theory an doesnt study a lot.
This is just childish megalomanic behaviour to create some “aura” of being a genius.
My point : i guess every chessplayer tends to underestimate his on time over a book, some underconsious most partly consious, both ways they tell to few hours of studying.

We all know a 2200 Fide player screaming around : I do not study endgaems, or openings, the same dude, blitzes down a 20 move long variation of the najdorf, or mates someone with bishop and knight in 30 sec

Come on be honest

I?Ǭ¥m pretty sure that you can take every young player(16-30 years) with rating 1800 FIDE and train him to become weak IM strong FM in 2-3 years if he practised 8 hours a day with say dvoretzky .
I guess to learn a good opening repertoire on IM-Level takes it 7-12 months. Endings, tactics 6 month each this should to the trick