Removing the social expectations, it is a bit odd to take hundreds of dollars from each of your friends to have a party that you have full control over. I wouldn’t expect my friends to fund anything in my life. But hey, I live in a country that can’t even crowdfund healthcare on a national level so maybe my view is just skewed.
At least half the money is used for the guest’s experience (food, open bar and so on) including return gifts (as is the norm in Japan). This is generally a gift catalog which guests can choose an item from. It is surprisingly fun as it feels like you’re not the one spending more way. They have catalogs of different values to need individuals’ needs.
Close friends will often plan surprise acts to be performed during the wedding (singing or dancing and so on). So it is not entirely up to the host.
It is still customary to invite one’s boss and co-workers too. So yeah, it is culturally different from western countries I guess.