Middle class by definition means that people are able to save and build up assets such that by the end of their career they can comfortably retire and pass down

Middle class by definition means that people are able to save and build up assets such that by the end of their career they can comfortably retire and pass down some wealth to their children. i.e. they make money from both capital and labor. Just because peoples standards of living are rising, it's happening in a way that is keeping them a part of the working class who is entirely sustained their whole life by making money from labor and never capital.