With 2019/20 regular season in the books, Ovechkin and Bobby Hull seem more and more joined at the hip and they are now very hard to rank more than a few positions apart (like the recent top100 project somehow did).
Bobby Hull's strongest suite was his goal-scoring. It seems that Ovechkin is currently already ahead in this regard. Consider this: in Bobby Hull's years and the rest of the O6-era, an average winner of the goal-scoring title led #10 in goals by 45%. Bobby Hull cleared that watermark 8 times in his career.
In Ovechkin's era (1996-2020), an average winner of the goal-scoring title led #10 by 27% - Ovechkin cleared that watermark 9 times (the difference being this 2019/20 season, in which Ovechkin led #10 in goals by 41%).
Also, Ovechkin eked out two more goal-scoring titles in addition to that (26% and 24% in 17/18 and 18/19). Hull's 9-th best margin was 32%, a far cry from an average Richard winner of his times, and his 11th-best margin is just 19%. So Ovechkin now leads 11-8 in "Rocket-worthy" seasons.
Similarly, Ovechkin seems to be gaining an edge on Hull in terms of longevity. Both have 15 NHL seasons now, but two first seasons by Hull are nothing to write home about, and in addition to that, he has a 56-in-67 season at the age of 22, a good comparable to Ovechkin's 65-point season in 11/12, and a 62-in-69 season at the age of 24, which would be worse than anything by Ovechkin except for his 69-point season in 16/17. So in the end Ovechkin has two extra elite seasons on Hull.
As for the tired narrative that Bobby Hull was Bobby Hull for a whole decade, and Ovechkin declined a lot after 2010 - Bobby Hull did not start nearly as well as Ovechkin, Hull's dominant years fell between age 25 and age 29. Yes, Hull was winning Art Rosses pre-25, but Hart voters were not too impressed and voted him behind a 37-year-old Harvey.
In fact, Hull's late 20s are very much like Ovechkin's early 20s (an Art Ross, back-to-back Harts, a string of Hart nominations, several goal-scoring titles), and Hull's early 20s are very much like Ovechkin's late 20s (not the same player, but still a Hart-worthy season here and another there, some inexplicable down years).
One can still argue that Hull's peak was longer and maybe higher, but then again, Ovechkin has a meaningful longevity edge already. So they are really close.