however the Rabbis who perform the weddings can tell the people that they will not perform the wedding without the pre-nuptuals
They could also refuse membership to those who don’t keep halachah.
And saying chareidim don’t seem to care and that causes chillul Hashem seems backwards to me.
In fact, a huge chillul Hashem was caused not too long ago when a chareidi “beis din” was caught going TOO far to enforce giving gittin.