I guarantee you the "let's just surrender" crowd in Iran is screaming their heads off right now, and the hardliners are scrambling to shut them up.
it takes a country a few weeks or months to actually get into war mode. They have to purge the disloyal guys, fire the useless commanders, let the troops get over the "oh crap" shock, and actually learn how to fight on the fly.
That's why the attacker always tries for a knockout punch and a fast peace treaty. They want to win before the defender can figure out what they're doing.
Caving and asking for peace right at the start is the dumbest possible move for the defending side.
Honestly, if they don't learn to take a beating and dig in like the Yemen, they're just gonna become another Iraq, Syria, or Lebanon. Just look at what a complete disaster it was for Iraq after they rushed into that Gulf War ceasefire.