In the final scenes of Thor: Ragnarok, exactly one movie prior, we see Thor fully realize his God of Thunder might against Hela. It's not quite enough (huh?) and Surtur is who does in Hela (at least we are led to believe that...)
Opening scene of Infinity War, we see Thor bested by Thanos and Children of Thanos members. Ebony Maw easily subdues him with metal from a ship that is not of Asgard (ship comes from Grandmaster's collection on Sakaar).
Is Thor's powers only tied to Asgard's existence? He makes one attempt on Thanos after Hulk fails... without using God of Thunder powers.
We know Thor's power isn't necessarily tied to wielding a Nidavilir forged weapon like Mjolnir, but I'm still wondering how Thor, God of Thunder, is completely bested by Thanos, granted with an Infinity Stone.