Pop culture is a dominant culture. It is one in the same,right or wrong.
In terms of the general public:
Batman, Superman, Wonder Woman, Spider-Man transcend comics/movies. They are pop cultural icons. You don't have to see their movies or read their comics to know who they are. Their influence span decades, generations.
Hulk isn't on their level, but he is 2nd-tier in that he is well-known like that beyond comics/movie buffs.
the difference between though, is that batman superman spider man and the hulk still sold mechandise, video games(not so much superman, but hes kinda been tainted) and tv shows. wonder woman was coasting on name alone from her 70s tv show, which the hulk also had and was also very popular and hadnt had a promotional push until probably the early 00s justice league. the hulk has been in the public eye just as long, but stayed relevant for a much longer peroid. the hulk is indeed on their level.