You say ''unless he was challenging for the Art Ross'' like it's a bad thing.
It is not a bad thing to be in the running for the Art Ross.
But the fact that when Jagr finished top10 and even top5 in points, Hart voters and All-star voters wanted no part of him - this fact is not a good thing at all.
At the very least, that fact tells you that valuing Jagr by his points would be overvaluing him.
Ovechkin, on the other hand, is often voted on All-star teams and gets on a good number of Hart ballots if he simply finishes top20 in points. And people here are calling OV "one-dimensional"
And why would you compare Ovechkin and Jagr by their voting ballots after 30? Ovi is 35. That's pretty convenient that Jagr left the NHL at 35 only to come back 4 years later.
At 33, Jagr placed 2nd in Hart voting
At 33, Ovechkin placed 7th in Hart voting
At 43, Jagr placed 7th in Hart voting
I'm not even sure how you can twist you way into giving Ovechkin the upper on those yet either.
Post-30 career is usually a good measure of longevity. Ovechkin has been on at least 15 Hart ballots in his age 30, age 32, age 33 seasons. His All-star team record in those years is 1x 1st, 1x 2nd, 3x 3rd - and that's ignoring the 4 Rockets, a Smythe, and the fact that "age 30" cutoff is not kind to Ovechkin - his Hart runner-up season of 2014/15 just misses the cut.
After Jagr turned 30, he was a Hart runner-up once, and then got on a fair number of ballots once more, as you correctly say. In terms of All-star voting, he only got on the 1st team once, and then got nothing (which also begs the question of why Hart voters voted Jagr over Tarasenko and Pavelski, but All-star voters emphatically did the opposite - were the Hart voters just trying to give Jagr a farewell gift in appreciation of his career, not as much of his play that season?)
Just like you say, I can't see how you can twist that to claim that Jagr's post-30 career was better and he aged better. Maybe you can point me to a KHL season that screams "if that guy had been in the NHL, he would have been on the 1st All-star team" - I personally do not see such a KHL season in Jagr's record. He was simply a ppg player in KHL - Radulov was like 1.5 ppg player there, he came over and then what? Not much happened.