Agree with this.
Plus where is the urgency coming from on the American side that they're so willing to cause widespread destruction and potential warcrimes for the sake of getting an agreement on a tight deadline?
The regime doesn't care about death, either their own or that of their citizens. On the contrary they see it as martyrdom. They recently gave a statement where they said bridges could be rebuilt but the opportunity to teach America a lesson comes only once. They have very little to gain from surrendering - in their eyes they have more to gain from digging their heels in and making demands that they will not veer from.
Larijani is dead, however his Kantian perspective lives on - in their view it is not the outcomes of actions that matter, but the actions themselves. The reason Iranian officials do not concede on certain points is because they are core tenets of their belief and they are seen as non negotiable.
In order for America to make headway with meaningful negotiations, they need to stop trying to strong arm on points that the Iranian government will never capitulate on and focus on where actual movement can be made.
Some progress had been made on these fronts in the negotiations that were held days before the war started. Now it seems that America is struggling to even get to status quo, let alone improve things from what they were pre-February. They've now managed to kill a bunch of more "moderate" members of the Iranian leadership, enable more hardliners to take their place, and weakened their diplomatic capabilities by sowing distrust and undermining the value of sitting down for negotiations.