I understand your perspective but from a different angle as a single girl.
It is hard to be alone and sometimes when you see other ppl’s families it just makes you realize what you r missing.
Sometimes, I really am happier eating myself than going out.
I sometimes invite younger girls (such as seminary girls who are looking for shabbas invites) to join me for a meal and that enhances it (and they help with the cooking-lol).
I also have a few families who I am at home with and don’t feel like a guest.
For the seder, I think as a one time thing I would not want to be alone but its up to decide you what ever is best and will make u enjoy the holiday the most.