Bobov was a Rebbe’s child. Belz was a child of a rebbe’s only son and obvious heir.
TLIK: I am maskim that the roshei yeshiva get a bigger bash than we do. But when rebbe chasunas host twenty thousand who come and make a week’s trip out of it, and rosh yeshiva chasunas get two thousand people who come for a half hour after night seder, I don’t get the comparison.