@perspectiveonthings,
I understand you're upset about the lying. However, consider this.
A bar or bat mitzvah is, by definition, a party that's really for kids. Yes, it's also family-oriented, and it's nice to see everyone when it's not a funeral.
By the time you hit age 40 or so, you have likely been there, done that with every single possible bar/bat mitzvah variant there is. Most of the music will be stuff that's not in your wheelhouse. Kids will be running around playing Coke and Pepsi or Name that Tune, much like when we were kids (I was 13 in 1975).
If you stuffed cotton in your ears and compared 1975 to 2024, the only real differences you would see would be hairstyles and clothing, and how much everyone has aged (and, often, put on weight). And... that's it.
The last mitzvah I attended was January of 2020, just before Covid really hit. In all seriousness, the main thing I can recall about it is that they played Bon Jovi's
Living on a Prayer, people raised their fists, and it was probably the most New Jersey thing I think I have ever seen.
And... that's it.
Of course you and I aren't going to have identical experiences, but don't forget the number of times you have sat at a table at a bar or bat mitzvah and wondered why you were bothering to get dressed up and go.
Of course they should not have lied to you. But this may not have been the horrific betrayal you are seeing it to be. Consider flipping your perspective. It may help.