I mean democrats categorically support unions, support reproductive rights, support protecting the environment… They do have a platform that isn’t “not Republican”. It’s just that republicans know their platform (project 2025 really) is so wildly unpopular they have to focus not on that, they have to focus on tearing down the opposing candidate.
In terms of helping the working class: taxing the wealthy and wealthy corporations more will help the working class. Improving access to low cost / affordable healthcare will help the working class. Having strong unions will help the working class.