Stop me when I say something inaccurate...
Most (or certainly many, if not most) people on these boards are anti-capitalist, and do not align particularly closely (or at all) with the Democrats (or Labour for that matter, the argument is transferable across the Atlantic).
Most would see more value for the working class from collective and community action rather than putting their faith in politicians. Many are actively involved in such movements.
Most recognise that for certain marginalised groups, things are demonstrably worse under a Repuplican/Conservative government (e.g. LGBTQIA+, minority ethnic groups, women) than they are under a Democrat/Labour government. See the Republicans using the Handmaid's Tale as an instruction manual when it comes to women's bodily autonomy; say what you like about Joe Biden and Co, but it seems unlikely that they'll be pushing to criminalise early-term medically necessary abortion any time soon.
Many would therefore not consider voting for and electing Democrat/Labour politicians as an end to their political engagement, as any form of solution to the ills of working class people, but would do so and then continue with their collective and community action to whatever extent each and everyone sees fit. Nothing will have changed, other than the starting point towards the post-capitalist utopia not being a Christian fundamentalist Republican administration and/or Conservative kleptocracy.