Marvel put in the work to build their universe. The others want it to just happen overnight.
And the biggest thing really is Marvel made a good movie and added a couple of hooks they could build on if it worked. They wanted that universe but they knew step one was the first movie needed to be successful financially and critically. Everybody else seems to be trying to make a universe first. We see the same thing happening in TV where folks hoping to make their show prestige are building this great 5 year arc but are totally forgetting that the first episode needs to entertain, and then the second, etc etc until you eventually have a good season. “Man we’ve got some great stuff planned for season 3” does you know good if the first 4 episodes are boring and you get canceled.