It only seems like a platitude because such a large number of working-class people have decided to piss away the meaningful assistance they would have gotten from Democrats in favour of the bigotry, bluster, and ignorance that seem to more immediately dance in their hearts.
That sounds harsh, but IDGAF. They vote against their own interests because something about having the hardships of racialized people get attention irks them. Seeing the successes of racialized people irks them even more. Having to check themselves or make an effort to show empathy to who are different? How dare we ask they do that! Too much economic angst, I suppose...
However, it is worth pointing out that you are operating as if "working families" includes only white families. You lament identity politics while playing that exact same game yourself. So don't tell me identity politics is bullsh-t when Republicans have warped it even moreso to their advantage (take Trump's silly politicization of the young lady who was killed by an undocumented immigrant, for example). By and large, working people do vote for Democrats. They're just working people who happen to be people of colour. But for some reason they don't count.
Clearly some former Walmart board member who gave a lot of secret speeches to Wall Street for lots of money was in their self interest.