Beis Yaakov rents its space for bas Mitzvahs.
I dont think anyone here is advocating a huge over the top party
Ive seen the gammut of Bas Mitzvahs from nothing to Home partys to Beis Yaakov lunchroom , Shul/School Simcha rooms to halls to over the top with a DJ and dancers and fancy food.
Nothing wrong with giving your daughter a special day, She will remember it for her whole lifetime.
The only argument I have against a home party is you have to setup cook serve and clean for all the guests. You cant enjoy the party and the nachas. Let someone else do the setup cooking serving and cleaning