From what I gathered so far:
Gallium is exclusively produced as by product of other metal production, mostly aluminium with a small amount from zinc. The yield is very low compared to the primary product. So to produce industrial quantity of gallium you need to be a major aluminium producer to start with.
Annual aluminium production:
Aluminium production is very strongly corelated with electricity generation because its very energy intensive to make. That's why you get paid to recycle aluminium cans unlike other stuff because this is one material that's very worthwhile to recycle.
Annual electricity generation:
1/3 of the world's entire generating capacity is in China. China's industrial electricity use is five times that of US, twice that of combined G7 and makes up more than half of the entire world's industrial electricity usage. There's a reason why China owns 95% of the world gallium production.
Although gallium is not a rare earth metal, it's used in similar ways like an industrial MSG. You need small amounts of it in a huge number of things from LED to solar panels to chips. Most of it would be consumed in China itself. Export market is very small and maybe only a few dozen million USD a year and is trivial amount for government to subsidise if they want to stop export entirely. To replace China's production will require many years and huge investment to rebuild the production chain, doubly so if there isn't already an aluminium production and associated electricity generation capacity in place. By the time you're nearly done China could also easily resume export and sell at below cost price (again, it's very easy to subside given the small size of the market) to crush your investment.
And as mentioned earlier the remaining 5% of the world's production is mostly Russia and parts of Ukraine that Russia controls. You could pay exorbitant prices to buy some from them but then again you'll be funding Russia's war effort. And Russia could always try to shutdown any remaining Ukrainian capacity by you know, bombing their electricity generation and distribution system.
