The definition is worse than that. It divides people who actually have similar class goals. Let’s convince small business owners that they are the same as the wealthy so the wealthy can further consolidate their power while we fight about who belongs to what group.

are* not class differences.

Cultural and political differences and not class differences. Your attempts to try and define who is in what class consistently ignore the fact that class is distinct from these other things. It’s also okay to be nuanced and say that working class is hard to define in the modern era.

There’s no reason to arbitrarily define the working class in ways that further erodes potential solidarity amongst groups that could make meaningful change. Small business owners are distinct from labor that doesn’t mean they are the same as wealthy oligarchs.