The real test is to look at the other Japanese cities that weren't bombed.
I've never been to Japan, but my understanding is they all look pretty much like this.
That means the bombing had little to do with it.
Well, most other cities weren't
nuked, but EVERY significant city in Japan except Kyoto was bombed to buggery and totally flattened. Well, that is not absolutely true, but about 98% true. The conventional bombing campaign went on for months, and killed far more people than the nukes did.
Tokyo, Osaka, Nagoya, I could mention others I went to; almost every single "historical" building is a ferro-concrete post-war reconstruction.
The reason modern Japanese cities all look modern is because they were all rebuilt after the war.
Kyoto was super lucky. It had very little of military significance. It was known to have hundreds of amazing historical temples and shrines. But it's luckiest break, according to stories I heard while in Japan, was that the USAF officer in charge of selecting bombing targets had been to Japan and even spent his honeymoon with his wife in Kyoto, and his wife kept nagging him to not bomb kyoto.
Lucky break, it is an amazing and beautiful city and about half of it is now UNESCO world heritage listed.
