Why is it never the Republicans who have to appeal to moderates?
You say that as if it's a negative for Democrats. But consider the growth of independents, and how many (of us) are -former Republicans-. And then look at the (appallingly bad) Democratic candidates for the last several Presidential elections. The Progressives are right about one thing: It's the Democratic Establishment that has failed not just the party, but the country. The last time I actually voted for someone, as opposed to against the other person for national office was 2016.
When Democrats start nominating candidates who lean towards the middle, and who abandon the politics of identity for policies that appeal across racial/social lines, they'll start winning competitive elections and even start to swing formerly Red districts (look at Texas Senate!), and then have an opportunity to govern. And I think we're starting to see cracks in the MAGA dominated Republican Party. Those will continue in 2028. It'll take a long time to recover from the bi-polar politics we currently have.