Birthday party no-shows... is this the norm?

My daughter's 5th birthday party was yesterday. She has never had a real party (aside from her 1st, which she doesn't remember). We invited her whole class (17 kids), and family friends. We rented out the gymnasium and we were expecting 30+ people (based on RSVPs) so we got tons of food, cake, party favors, etc.

The day of the party multiple people notified me that they wouldn't make it and a bunch more that RSVPd "yes" just didn't show. The only people who showed were two family friends and grandparents.

I'm grateful that we had at least a couple of kids show, but my daughter kept asking when "so and so" would be there. It was honestly pretty heartbreaking because she was so excited and it wasn't much of a party at all. We've been to all of the birthday parties for her classmates and there's usually at least a handful from her class that show, but not a single one came to hers.

Is this the norm nowadays? Next year, we will probably just do an experience birthday instead.