Thor: Ragnarok was the third movie in the Thor: Trilogy, but it more or less felt like a new beginning for the God of Thunder. Not just him but the Hulk also began a very new story arc that has its major ups and downs like a big roller coaster ride. Ragnarok is the movie that really began setting up Avengers: Infinity War, and then the means for Avengers 4 were laid down.
Avengers: Infinity War really brought forward Thor to his peak strength. It was basically a movie where Thor, the strongest Avenger as of now got the most important throughout Infinity War as a new story arc was written for Thor after he re-established himself in Thor: Ragnarok. He also began a new arc which went on the contrary to Thor. Ragnarok sort of introduced this new Hulk, who can now speak, and has been the Hulk for two years now.
Then, when you feel the Hulk is at his best, Thanos comes in and scars him for life. The Hulk gets a beat down that he has never faced in his entire life! He comes in to smash but gets literally smashed by the Mad Titan. Even before Thanos when the Hulk fought Fenris the Wolf, you could see that it took him quite a while to take the Wolf down as it turned out to be a pretty savage battle. Then he attacked Surtur and had no effect whatsoever on the Giant Mountain sized villain. He was thrown away like a little ant!
If you really count the fights the Hulk had been in since Thor Ragnarok, you could easily notice that he just barely won once against Fenris the Wolf, and lost to Thor, Surtur, and Thanos! You could say that he was not able to unleash his full strength. Now this insane new theory that is circulating around the internet could give an answer to why he has been down on strength lately.
The theory suggests that right after the Hulk went through a portal in space and ended up on Sakaar, he was picked up by the Skrulls, and one of the stronger Skrulls shapeshifted into the Hulk, learning quite a few things about him and Bruce Banner. The theory suggests that the Skrulls have been planning an invasion right from the moment their first encounter with Captain Marvel ended badly. So after somehow getting hold of one of the biggest guns from Earth, The Skrulls got to know quite a bit about Earth itself.
This is the reason why the Skrull Hulk faced so many beat downs in head to head confrontations. It was because he did not actually have the access to Hulk’s entire strength. Just imagine, if this turns out to be true, then this Skrull agent will have learned so much by being the Hulk for all this time. He now knows the weaknesses to Thor, has been to Earth talking to Tony, been in the Avengers facility, flown around in the Hulkbuster armor and has seen the secretive Wakandan technology which could be studied for a future invasion.
The fact that the Skrulls are rumored to be present on Earth as Yakuza in Avengers 4 could work very well with this reveal of the Hulk Skrull. No matter how insane and surprising it is, it is really quite a lot to take in. This would demand a major explanation and if this is the extent that the Skrulls could shapeshift as someone, knowing about their past, having access to their partial knowledge, strength, and skills, then the people of Earth will really be doomed if the secret invasion storyline does take place.
But this turning out to be true is highly unlikely as the story arc for the Hulk since Ragnarok has been set to run through three movies. Ragnarok brought aspects of the Hulk that we have never seen in the MCU, and Infinity War really improvised on that giving him a major beat down and fear. Now, Avengers 4 will bring out Hulk at his best, probably introducing Professor Hulk, where Banner is control of his mind and Hulk’s strength. This is how the Green Goliath would get over his fears and rise to being the big smashing gun of the Avengers that he is! Avengers 4 comes out on May 3, 2019.