In East Asia, Japan in particular, most "old" buildings are reconstructed fairly often. They might reuse a lot of the old supplies, but many are very much a Ship of Theseus. Roman structures are, for the most part, preserved as they were--not fully disassembled and rebuilt.

One thing is that most places with extremely old structures have them far and few between. A 2000 year old building that wasn't rebuilt from the ground up is often a symbol of national pride for a country and seen as somewhat of a miracle that it's still standing. What makes Rome unique is the city alone is full of such structures, and it's a living, active city. In other countries that had a Roman presence, many of their oldest structures are remains built by Romans.

Most Egyptian structures were buried under sand for millennia and well-preserved as a consequence of that. I have to wonder how they'd hold up if they were in a different climate and with humans bustling about constantly into the modern era.

Either way, Romans were clearly doing something special.