Sulfur cools the planet but not by shading, it’s more similar to how CO2 acts but in reverse.

That’s not really relevant. Fine particulate emissions from coal power plants, which are already mostly gone in the US but are still used around the world, don’t travel a really long distance.

F35 is guaranteed to be better than a “6th generation” Chinese plane and they can be upgraded anyway. And it’s actually very successful now with a very cheap per plane cost.

It’s more about sensors and communication, there’s no reason you can’t have f35 use drones and stuff. But the better plane will see and target the enemy first. And it can operate without GPS. In other words it’s better to have 3000 f35s flying missions plus a bunch of drones. Being able to deliver a lot of firepower first is a huge deal.