Biden’s narrative was that we need to have a big raise in corporate taxes, spend almost a trillion dollars finally doing something about climate change, bring domestic manufacturing back to the US and give people working-class jobs again.

That was his sales pitch, and one that I am totally behind, but those are promises, not a narrative. His "big raise" proposal wouldn't even return rates to where they were before Trump slashed them. Policy promises sell to policy wonks, but most policy wonks are tired of two steps back, one step forward.

When I say narrative, think of a movie plot. Narratives require a hero and a villain. Had Biden framed multinational corporations as the villain, and set himself up as the hero that would take them on, then he would have had a narrative, but that's not in his nature. (Which is part of what qualified him for establishment and corporate media backing in the 2020 primary.) Biden would have been a perfectly good Democrat back in the 90s when people were a lot more optimistic about their futures, but that was no longer sufficient. In the 2020 general the Republicans handed him a monster to slay in Trump's complete failure to address the epidemic, but that story was old by the 2024 sequel.

like that inflation was all his fault

Yeah, that was unfortunate and complete bullshit. Whatever philosophical differences I have with Biden, we was certainly a competent manager of the economy. The inflation wasn't even all that bad, only lasted a couple months, and America kept it lower than anyplace else in the western world. However, a more aggressive and energetic candidate, maybe even a younger Biden, could have gotten that message out. I don't want to dwell on that too much though, because that's too specific to the 2024 election. Anyways, there will always be something that goes wrong and hurts an incumbent.

But the Democrats didn’t get this way overnight or by accident. It happened on purpose, through natural selection and legalized bribery and threat.

Yes, a lot of it was externally driven, but it was also a strategy choice going back to right after Republicans embraced the southern strategy. A great easy read on the topic is "Listen Liberal" by Thomas Frank, author of "What's the Matter with Kansas?". Democrats made a conscious decision to abandon working class Americans in favor of urban professionals. It wasn't a slow devolution, it was a pivot.

And, also, any time they do do something good, someone like you comes along and makes sure to shit all over it and “call balls and strikes” and try to “put it in context” and try to cancel it back out again.

I guarantee you that Republican voters aren't listening to someone like me. Also, my language before a general election is quite a bit different than after. This is the time for Democrats to learn and refocus to doing better next time. I don't compromise my principals before an election, but I spend a lot more time pointing out that whatever flaws the Democrats have, they are miles better than any Republican.

Despite your assumptions, I do a lot of posts defending Biden when he's being treated unfairly. I also frequently comment about Trump and the Republicans, but not as much because the internet is absolutely flooded with comments like you describe. It just feels redundant to keep pointing out how shitty Trump is. For a while I was pointing out that he was going to be worse than many people expected, but I think the hive mind is pretty much caught up on that now. I also post differently on Lemmy than on other social media. Lemmy is mostly a left leaning space, so there is not as much reason to attack Trump here. On other platforms I spend a whole lot more time debunking Republican lies than anything else.