Millenials definitely were called enitled and lazy when they were in their 20s. Theyre in their 40s now, now the supposedly lazy generation is Gen Z. Every generation has called kids in their 20s entitled and lazy. In about 15 years Gen Alpha will be the lazy and entitled generation.
That said, it is a big hole in this theory. Gen X and the Silent Generation seem to only be remembered by how they behaved in their youth, and Gen Z seems to be following that trend.
Did some digging, and Gen Xers were best known for being helicopter parents. This was in reaction to how their parents barely paid attention to them. They are the only generation that gets hate for being helicopter parents, as far as I can tell. They seem to be the Soccer Mom generation.