The failed presidency part certainly checks out. There's a decent chance that Democrats, if they can win a 2020 trifecta, can sustain power for a long period thereafter (especially if they're smart enough to admit some new states). The demographic trends that made people (too) confident about 2016 still are in force, after all, and it's at least arguable that Trump was the last hail mary gasp of unadulterated conservative White male resentment as a driving electoral force.
The biggest difference is that while Carter was a wonderful ex-President, Trump undoubtedly will be every bit as wretched after being turned out as he was in office.
All that said, I can't help but be pessimistic about what can accomplished in a (knock on wood) Biden administration. That's not a knock on Biden. It's rather a reflection of the sober reality that it will take an inordinate and disproportionate amount of energy and resources by a Democratic administration simply to repair and remediate the mess Donald Trump has created, leaving little time focus on any genuine positive change. Just getting back to square one would be a massive accomplishment, let alone advancing the ball.