I think a big part of it is that
>>104898625 is right and Aquaman is this season's "spectacle" movie, like the Hobbit movies were three years in a row back in 2012-2014. They were movies that had huge setpieces and incredible things that you felt compelled to see on the big screen. Aquaman's the same way, and for good reason; the movie is genuinely going to be shittier on a TV because there's so much spectacle happening visually.
Bumblebee, meanwhile, seems at first glance like a smaller, more intimate movie, even though it has giant robots. But it seems like something you could potentially wait to watch on Netflix, even though I plan on seeing it in the theaters.