At this point I think they know 2022 is gone, and are aiming for a fighting chance in 2024. The only real difference between a president bernie and a president biden, is that in 2023 and 2024, leading up to the election, when the republican congress refuses to do anything, Bernie would sign EOs that would help people, and Biden just MIGHT sign them (being able to use the excuse that republicans wont work with him to do it).
IMO, the only good thing that was ever going to come from these 4 years was not having Trump as president, and possibly an EO reducing student debt and an EO rescheduling marijuana. Nothing else progressive was going to happen even with a president Bernie. And those two EOS might still happen from Biden, but who really knows.