who was able to gain more during Obama’s presidency, the tea party or Occupy?

That's a fair concern. The differences I see here are:

1. Obama ran as a progressive and it took people a while to figure out that he wasn't overly serious about progressive causes (much less anything anti-capitalist). Most people don't think Biden is a progressive in the first place, and any thin "most progressive in history" veneer he builds up in the campaign won't last even a few months, as he has no actual progressive policies he wants to implement.
2. Speaking of anti-capitalism, direct critiques of capitalism were still far from the mainstream for most of the Obama years. Occupy was seen as radical; you didn't have polls showing significant numbers of Americans being open to socialism. Look at the few left-ish politicians we have today, and look at how many of them were in office during the Obama administration. Look at the budding leftist media ecosphere today, and look at how many of those outlets were around in 2012, or even 2015. Anti-capitalism is a much more powerful and comprehensive organizing tool than a lot of progressive talking points, and anti-capitalism is at least on the periphery of the mainstream today in a way it wasn't several years ago.
3. Back to Obama: he was charismatic as hell, young, and he had very little Washington baggage. That's all pretty appealing to the type of young, newly-political person leftist grassroots movements need to really take off, and Biden has none of that. There was never any chance Obama was going to get primaried or not run for a second term. There's a real chance Biden could do either.
4. Because Obama was so superficially appealing (especially in the wake of Bush), many ordinary young people bought in to him -- they campaigned for him, donated to him, had an Obama bumper sticker, etc. They would have needed to reject all that, i.e., admit they were wrong, to really buy into a leftist alternative. Admitting you were wrong is hard! No one is really buying into Biden this time around, especially young people, so moving on to an alternative will be easier.
5. Obama is black (no way!) and received an unending stream of racist attacks from the right. That made right-wing organizing against him easier, and Biden being white will make right-wing organizing harder. On the left, the simple fact of Obama's presidency was (justifiably) seen as an enormous achievement. Not only was a black man in the highest office of a white supremacist state (which is significant, even though the "more women drone pilots" critique certainly applies), but he was both a victory over the Bush-era neocons (literally some of the worst, most dangerous people on Earth) and an alternative to the Clintons (sleaze, careerism, dynasty politics). That's a lot harder to attack from the left than Joe Fucking Biden.
6. Obama did plenty of bad shit, and Obamacare has many flaws, but Obamacare also does some legitimately good things and was a real, highly-publicized legislative achievement. Biden will have nothing similar to hang his hat on.
7. There was no Sanders campaign in the 2004 and 2008 primaries -- i.e., there was no genuine, popular, openly-leftist alternative to the centrist/neolib Democratic establishment. The (relative, not complete) success of Bernie's 2016 and 2020 campaigns showed voters that supporting a similar candidate in the future isn't unrealistic, and it opened up some space for leftist campaign staffers to gain some experience and have the possibility of a real career.

Maybe this is all too optimistic, but at very least there are some real differences between today and the Obama years that make direct comparisons difficult.

you can bet on liberals not wanting to join any resistance to Biden since they’re not paying attention now that Trumps gone just like they didn’t pay attention during Obama’s presidency.

This is where I think the shift from a progressive left alternative to an anti-capitalist left alternative has the most power. I think it has greater potential to draw in people who don't ordinarily vote, and for the progressive liberals who just want to go to brunch without worrying about what the president tweets, an anti-capitalist alternative is a lot farther from Biden than any more progressive alternative would have been from Obama. There's more contrast when your framing is capitalism than when your framing is "does this guy talk the talk on moderate reforms."

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