I think at this point in his career, the Senate is probably best for him. We need powerful progressive senators to pass progressive legislation.

I've seen this sentiment expressed before and I agree, it's a reasonable view. I'd still enthusiastically vote for him tomorrow if he could be on the ballot instead of Biden. I am not a strident hater of Biden, but I agree with most of the (non-maga) criticisms against him to one degree or another. No doubt I'm picking him over Trump, but I wish we had better choices.

Which is something important I want to highlight – Clinton scorned Bernie, while Biden welcomed him. Biden was friendly to him in the Senate, and that set them up for a successful cooperative future.

Yep, I don't keep a spreadsheet of these sorts of things or anything, but I remember claims during the 2020 runup that he would at least take advice from progressives under advisement, and I get the feeling that he's lived up to that much, at least.