In the latest episode of What If?, Odin never adopts Loki and so without Loki testing him through the centuries, Thor becomes a "frat boy" who constantly wants to party. When he brings the party to Earth along with Asgardians like Sif and frost giant Loki and a bunch of aliens including the Grandmaster, Nebula, Korg, and Howard the Duck (all voiced by the original actors), SHIELD gets involved. Korg accidentally injures Fury though so Maria Hill has to take over and she summons Captain Marvel back from space because she fears Thor's partying will destroy the entire planet.
Maria Hill says that one Captain Marvel punch is equivalent to ten nuclear bombs and that she should beat Thor. Carol starts the fight by punching Thor, who isn't interested in fighting. But then she punches him again when he's still trying to talk it out. Then he hits Carol and knocks her from Paris to Stonehenge in the UK. She lands against one of the stones and almost knocks it over, but she uses her super strength to steady it. Thor arrives and when Carol tells him to be careful around the landmark, Thor taps one of the stones with one finger and knocks all of Stonehenge down. This really pisses Carol off and she punches Thor over 5,000 miles from the UK to Monument Valley, Utah. Thor gets up like nothing happened.
They exchange numerous blows until Carol knocks Thor away. He uses Mjolnir to shoot lightning at her, which does absolutely nothing. I assume her power is still like the comics and she can absorb energy. Thor is surprised by this, and she delivers a huge punch that knocks Thor into the ground creating a giant crater. He gets up again and Carol tosses him through the air again. She starts punching him and she's sending him over the tropical Pacific now, apparently over Hawaii. They land in some storm clouds and fight some more. Then Thor knocks Carol back to Paris. She's only stunned for a second, but it's enough time for Thor to put Mjolnir on top of her and she's trapped. Thor then takes Mjolnir and walks away.
Carol goes back to Maria Hill who berates her, and Captain Marvel says if she uses her full power against Thor, it would create a giant crater in the planet. Darcy offers up North or South Dakota as collateral damage. Hill and Carol come up with a plan to get Thor to Siberia to finish him off. Thor is in Sydney, Australia, and about to slide down the side of the opera house when Captain Marvel blindsides him and knocks him to Siberia. Thor says, "I actually felt that one." They are about to clash again when Frigga appears as she was brought by Jane Foster. And that's the entire fight.
So there you have it. The MCU's big guns go head-to-head and more or less come out even. Captain Marvel was holding back some due to the potential for collateral damage, but Thor was clearly not fighting his hardest either as he never took the fight seriously. Carol looked better on points but part of that was because she was the aggressor while Thor didn't want to fight, and even despite that, he immobilized her in the first fight to technically win it. And the scale of the fight was planetary. They literally fought around the entire globe, starting in Paris and ending in Paris.
I take it all with a grain of salt. In the live action stuff, its at least implied that Scarlet Witch and Captain Marvel are tops, but you could make some arguments otherwise.
In the what ifs, Thanos seemed kind of wimpy compared to the guys who worked for him in the mainstream MCU when T'challa became Starlord...certainly didn't seem like someone who could beat down the Hulk.
That said, I thought the episode did a good job at keeping it vague enough and treating both characters with respect....much like the Thor vs. Iron Man vs. captain America fight in Avengers, and the Thor vs. Hulk fights
I do think the choice in the MCU to try to make CM and Wanda potentially clearly tops is a questionable one. I also think Endgame did a disservice to Hulk, and never gave him the chance to redeem himself as a physical powerhouse.
I have always felt the best way to handle it was to make Hulk pretty clearly the strongest, most durable, fastest healer, CM have better EP, speed, etc. with Thor being the best all arounder, so a reasonable argument could be made for any of them being the most powerful...throw Wanda into the mix as maybe even the most versatile with EP, but no durability and strength....fine....but that is a discussion for a different time.