That’s a very binary response. I agree that they should be doing more, but I also think it’s important to recognize what they are doing. Sweeping change doesn’t happen over night, and so far the actions I’ve seen in Biden’s administration lean pretty heavily away from past neoliberal trickle down. The attempted student loan forgiveness, the new head of the FTC, investment in infrastructure and jobs, Tax plans to reverse the cuts and loopholes for the rich introduced by the previous, capping capital gains tax (as in switching to income tax after a certain number is earned), a minimum income tax on people with wealth above $100 million, and much more. All of that is counter to trickle down economics, and some of it is even a reversal from Obama era decisions and Clinton era decisions. Bernie is definitely doing work in his position, a quote from a Guardian article quoting Bernie:

With a hearty laugh, Sanders, 81, recalled that, after the 2020 Democratic primary, his team and Biden’s had joined forces to produce an “agenda for working families”. They did not agree on everything but “put together probably the most progressive outline that any president has introduced since FDR” – a reference to Franklin Delano Roosevelt’s New Deal in the 1930s.

So yeah, I despise Biden’s past voting record and behavior, and I think we could do better. But it’s totally counter productive to act like nothing has changed in this administration without actually paying attention to what’s happening, the government is not just the president.