The US has had contingency plans to bomb Iran nuclear sites for years. Lots of analysts in and out of government have studied this extensively, and it's clear to sensible folks it's a bad idea (thread):
-you can push the program back maybe 1-2 years, but then you give Iran the... https://twitter.com/ewong/status/1328492151295143936

...best possible argument to rebuild - and you make a strong case that the best way to avoid a repeat attack is to actually build a bomb (see: North Korea: not attacked; Libya, Iraq: overthrown)
-the costs in terms of regional destabilization outweigh the temporary gain

-very important point here: Iran's defence doctrine is premissed on the idea of recognizing its vast conventional power deficit relative to the US and its partners, and to instead build an arsenal of unconventional tools not to defeat the US (that would be impossible) but...

...to impose costs on the US (its regional assets; partners). Iran could do that - a lot.
-allies would NOT be on board. I get it that Iran hawks don't care what allies think, but serious planning has to weigh the pros and cons in the bigger picture. Very costly here.

-For all their bluster, some regional partners of the US are not particularly keen on the US actually attacking Iran; they like the idea of the US threatening to do so, as a way of pressuring Iran (and it sort of works), but they fear -rightly - that they would be...

...on the first line of Iranian retaliation (and not the US).
-it would be illegal (I know, I know, hawks don't care here)
-it would kill innocent civilians

-bottom line, don't do it (not a coincidence that traditionally, much opposition to strikes on Iran has come from inside the US government, with the exception of lunatic political appointees).