Biden tried to restart the deal back in 2021, and has been trying ever since.
However, it turns out that the US is not the only party involved in international treaties. We can't just pick up the ball and go home mid game, then come back in a year with a new coach and expect everyone to continue playing like nothing happened
The original deal was a difficult achievement on its own. Now, we need to not only repeat that, but also deal with the fact that Iran does not trust us to follow through with our end of the deal. Overcoming that needs good negotiation, and a lot of concessions we did not want to make.
This is why administrations of both parties have historically upheld deals made by the opposing party that they didn't like. Unilaterally breaking deals every 4 years because of who wins an election makes the US a non-credible partner in negotiations. You can't just wave a wand and fix that.
People have been warning from day 1 about the possibility of a regional escalation.
Apparently you cannot spend months acting in a way that neighboors who already don't like you find morally reprehensible without some of those neighbors inserting themselves into the conflict.
The real question is how long can Iran avoid getting dragged into that. And if Iran gets involved directly, will we be able to contain this to a regional war, or will this small decades old conflict between parties whose total population is only about 12 million become the trigger for world war 3.