The bulk of the money goes to supply and transportation, which is usually a foreign state or a trans-national entity of some kind, far far from the point of consumption.

Mexico (in this example) could try to siphon off money through a tax or regularion or by investing capital in local supply, but the OP believes taxes/regularions are just a way to foreclose on any opportunity because the miners will just go elsewhere, and investing capital in growing local supply means redirecting it from somewhere else (assuming you can even make local supply price competitive without subsidies).

Some spending can stay local and benefit local economies. Spending on power is generally not one of those.

Both the mining itself, and many forms of electricity (especially the cheaper kinds), do not require a lot of labour.