Remember that things change very quickly in politics. The Republican Party was written off as dead and noncompetitive following 2012. The map looked nigh-unwinnable for a Republican prior to Trump, with things continuing to get worse based on demographic voting trends that were assumed to continue indefinitely. Demographic outreach following his securing the majority of whites, policy shift in remaking the party in his own image away from neoconservatism and interventionism, and turning blue states purple and purple states red was a seismic political shift. Perhaps once it's not specifically Trump on the ballot those gains may even reverse and return to expected levels, as well.
Democrats have a lot of issues in 2025, but by necessity and nature American political parties are reactive to appeal to the people and get votes. The 2030 census is going to present another massive hurdle as reliably red states continue to gain population and representation while blue states continue to lose population and representation, not to mention they're a party built on diversity who then have internal groups with conflicting goals and values (ask them about hemmhoraging both the Jewish and Muslim vote simultaneously somehow). Somebody will eventually step up as a transformative Democratic figure like Trump, a multiple individual movement will form, or they will seize upon Republican mistakes when the time comes. The coastal elitism and social justice zealotry is currently an albatross, especially when so many of those in their base are ardent believers in it (the ones voting in the primaries, hint hint), and you've already seen quite a few Democratic figures backing off of the hardline stuff on certain issues.
Rest assured that you can never, ever write off a political party in a two-party system. They'll adapt and be back eventually, perhaps as soon as 2028. It's going to be hard to get their people in line in the short-term as there is currently a complete vacuum of leadership, however, and they might continue to experience pain for the next few cycles as they figure stuff out and fight amongst themselves.