I'm 100% on board with this. While the "Genie doesn't experience time the same way" theory is also plausible, why would the genie be trapped in the lamp for 10,000 years and have a problem with it at all if time means nothing to him? Also, if time means nothing to Genie, why can he 1) get duped by Aladdin, and 2) do the things that allow Jafaar to use him to do terrible things?

Also, the Merchant scene really sets a lot of this up as well. The combination hookah and coffee maker also makes French fries - potatoes didn't even make it to the Eastern hemisphere until the 1500s. The Dead Sea Tupperware, obviously, sets the date after the 1960s.

Also, there's other lamps around. The vendor talks about a lamp, while handling a clearly polished lamp, meaning that it's not the Genie lamp. In the market scene, there are lamps at a stand as Aladdin and Jasmine run off. If Genie was stuck in a brass lamp for 10,000 years, it would have been made around +/- 9,000 BCE, before brass was first created. In fact, before writing had been invented, and Genie can read and write. In English.

Finally, that the Cave of Wonders would contain much of the world's gold mined up until the Medieval period. Estimates the global mined supply, including mined in ancient China and the Americas and not likely to end up in a cave, would be an order of magnitude more than estimates of what Scrooge McDuck had in his Money Bin, and the cave seems to have more than Scrooge had. There was no shortage of gold in Agraba - especially since we see gold elsewhere in the movie. Clearly this is the bunker of a prepper who used an advanced AI system to guard it all, stockpiled billions in gold coins, and died before they could spend it all.

Additional theory element: Genie experienced 10,000 years in the lamp because Genie was on Earth the whole time. During the apocalyptic event, several ships left the earth and used advanced propulsion to explore nearby star systems for a new home. None of them looked good enough, and after traveling at close to c for what seemed like a few years, some of the ships started to return to Earth (Edit: the first Planet of the Apes movie from the 70's had this as its plot), including the seed ship the AGRABA. The city was founded by a seed ship trying to repopulate the Earth. They were gone for what seemed like a few years, but due to time dilation, the journey from Earth's perspective was closer to 9,800 years. So the advanced technology makes sense still as newer tech scavenged from the seed ship and forgotten about, like the AI tiger head guarding the cave.