Its only seen a lot of play in EDH since its rotation out of Standard, both in the 99 and at the helm of some devastating aristocrats decks
Heidegger, Shinra Executive* Hasbro executives werent able to swoop in and make Heideggar a stronger card, as hes a mediocre Soldier typal card, mediocre control card, and a mediocre board catchup card
In Modern specifically, it still sees only moderate play compared to how many decks could truly play it, which is mainly a reason for Jeskai not being super popular right now
Well, a rotation means that a couple of sets will no longer be legal to play in the Standard format
I wish Ten Rings didn't cost 8, but we can't get everything we want in this life
Jace set the standard for the best planeswalkers in MTG by combining control, card advantage, and long-term inevitability into one absurdly efficient package