I wonder if there would be a way to have the Shenzhen/Hong Kong tech ecosystem while also having acceptable air quality. Hong Kong is probably my favorite city in the world, but the air is really bad (not quite as bad as Beijing or old Mexico City, but bad). I assume a lot of the pollution is due to less value-added industries and primary electrical power generation (using coal), which aren't really essential to a tech area -- you could run HVDC to send power from far away, or go nuclear. EV vs. ICE would move a lot of the transportation pollution away, and domestic needs could be more electrified (I think rural China still uses a lot of wood/coal burning domestically, which is bad for both indoor air quality and, in aggregate, pollution.)