When do kids stop having birthday parties?

My kids have only had a handful of bigger birthday parties each, so it's not something we've ever automatically done every year. We always celebrate with family, but most years they haven't been interested in a party with friends and classmates invited. I imagine that by middle school, we'll stop hosting big parties completely. We generally offer an option for either having a party with friends, or choosing a big gift or fun family experience to celebrate (theme park visit, theatre tickets, etc).