Kanye and Britney and Gaga and PSY were all more influential imo. The former two basically started the electronic pop infusion and whole synth pop, electronic pop, here's the drop pop, that helped get EDM exploding in popularity, which in turn helped resurrect the festival scene (see: Stronger). Plus 2017 saw rap finally eclipse pop and rock in numbers. Gaga's art pop vibe was aped by everyone for years, and even T Swift's new album and music videos still do. PSY basically pushed YouTube into full cultural zeitgeist and laid the groundwork for other Kpop groups like BTS and more to chart in the west.
Lorde's solid. Royals is one of her weakest so it's a shame it's played so much.