Well, I see the party changing and some progressives unwilling to acknowledge it. If this were 2001, you'd have a few Democratic House members negotiate with Republicans on the healthcare bill. In the Senate, Joe Manchin would be meeting with the secret cadre of Republicans working to craft the bill. Instead, that's not happening at all. Even vulnerable Democrats aren't joining them--that's progress.
What's more, the party will change if more progressives are elected. That's just history. The Democratic Party was once the party of racism and southern rights. After civil rights oriented Democrats from western and northeastern states began winning seats, the party changed, right? After Reagan's massive reelection in 1984, people associated with Gary Hart's campaign, a campaign that got the youth vote in massive numbers during the primary, formed the DLC. While we hate it now, at the time, it was a "fresh" ideas organization that came into vogue after the 84 loss. Its candidates began winning and the party changed then.
Right now, progressives are amped up, but we are actually in a pretty big rut. A party that hates progressivism, hates centrism, and hates anything that's not hard right, controls everything. I just don't see what fighting with voters who we need on our side achieves, let alone focusing on the Democratic Party as an unchangeable monolith, but that's me.