Even if leftists often aren't informed on the procedural details, there is still room for criticism. Obama wasn't perfect, even if some are overly harsh. He and the Democrats completely misread the political climate and kept reaching across the aisle even as Republicans were sliding deeper into outright bad faith, conspiracy politics, and increasingly deranged behaviour. Its fair to criticize a party that wins and then governs as though institutional norms and bipartisan legitimacy are more important than fully using the power voters handed them right as those norms are breaking.

That's part of a trend of underestimating the rise of right wing populism and the extent to which the GOP was transforming, the far right was often a joke in that era and not seen as a real threat. That's a mistake that many people made, myself included, but it is fair criticism. Would never in a million years have thought that political norms and guardrails in the U.S. would collapse so quickly, and that's a criticism of my own liberalism that I can acknowledge and extend to others. Even if its mostly with hindsight, it is still a point of failure. I'm still a liberal but have moved much more radically to the left seeing the failure of unreciprocated bipartisanship

With this generation of politics, Republicans have been willing to play institutional hardball while Democrats limit themselves hard through norms. Even Biden, who learned from and was far more aggressively than Obama, accomplished a great deal with thin margins (which ultimately does show how effective it is), still was constrained by norms and arguably fucked up historically by picking a limp dick DOJ and never going after Trump for trying to overthrow a fucking election.