McConnell made things difficult, sure, but Obama had a supermajority for eight months of his first term.

Biden had Manchin and Sinema, but he wasn't without recourse. He could have targeted Manchin's daughter for regulation or investigation, because her company price gouges for prescription drugs and kills people. Sinema could have been stripped of all of her committee assignments, which would have made bribing her worthless and impacted her financially as well as severely limiting her power as a swing vote.

But, at the end of the day, you pointed out the most critical thing. Presidents have power. They just need to be willing to wield it in order to create change. The reason you're seeing Democrats participate in fascism and pretend to be powerless is that it serves their wealthy benefactors and they're happy to take those $100k bribes, I mean, "speech" engagements.