This has always been one of my biggest "minor" fears for my kids. Sure death, major sickness, homeless are all up there, but of all the things to just mentally stick with you as you grow up, it's like my top concern.
I can't think of almost anything more devastating to a kid than having a birthday party, inviting all your friends, hyping up the day, prepping while the kids just prances around excited beyond belief, then nobody show up.
Luckily I convinced my kids of other options for birthdays; weekend trips, bigger family only activities, smaller sleepovers. They have almost entirely taken one of the other options.