No one came to a birthday party but my daughter

We went to a birthday party for a girl in my daughter’s dance class yesterday, and no one else came from the class. I was there the day they passed out invitations and saw that everyone was invited, so out of 7-8 little girls only my daughter showed up 😢. It made me feel sad to think if we hadn’t come for some reason she wouldn’t have had any other friends there. Her and her brother had a combined party and my son was invited to the brother’s birthday so he came to play as well, and the brother had like 15 kids there for his party but the little girl just had my daughter. They had a few young cousins there also. I felt so bad for the little girl but she didn’t seem to mind she was just so excited my daughter came and they had fun together. Idk why I’m posting this I just felt bad I guess, no one rsvps to parties anymore or goes to birthdays, and as a mom that just makes me sad.