I can only guess to the reasons why, but my two best cracks at the mystery here follow as these:

1. people actually like this cookie-cutter soap-opera formula juxtaposed to the cheesy melodrama of superheroes (which to me must be counted among the worst in the field of melodrama) 2. people just like Wandavision because other people told them so on various social platforms, and a slew of people are nigh completely ruled by peer pressure when forming personal taste.

In short, if you don't like soap-opera, pointless melodrama, corny, campy, on-the-nose arm-chair psychology, then avoid. This is coming from someone who can get down with Whedon's early stuff, I am not completely outside their target-audience.

This is my review 8 episodes in, the finale needs to pull an heroic effort to make me reconsider. I am glad Disney took a chance at something like this, I just hope they rinse and repeat with a better project next time.

+2 for Elisabeth and Paul and +1 for an original, but ultimately stupid, idea.