Stock buybacks are just a form of dividends. It's still subject to taxation via capital gains tax.

Subsidy is just a way to create an incentive for Intel to build manufacturing facilities in the US. It's not paid because Intel lacks funds, but to ensure that factories are built in the US and not elsewhere. Intel can do whatever it wants with the money received from subsidies, provided it fulfills its obligations.

Jobs aren't particularly important in this schema, but they are a nice talking point for politicians to show that at least part of the money paid via subsidies will return to American workers.