Boycott US

Assuming they're an American-owned, American-headquartered company, more harm than good is debatable, but they don't operate in other countries out of charity. It has to be profitable. And it's the profit that goes to America. Yes they build local factories, yes they pay local employees, sometimes they buy local commodities, perhaps they do a bit of local charity (usually for tax breaks) and in these ways they contribute to the local economy, but the profits go back home. And if they ever decide it's not profitable anymore, they will lay off most of those employees, sell anything that isn't easily movable or worth moving, and take all that money back home too. Some of your money stays local, but a lot of it leaves the country, sometimes the lion's share of it, and even more of it is only in your country temporarily for as long as you remain profitable.

That said, the reasoning breaks down with most of the megacorp brands you're familiar with. The billionaires that own them and even the less hyperwealthy executives are essentially nation-fluid black holes of money. It doesn't matter if they're "based" in your country, they will never pay tax, and your money will most likely never see the light of day again. It will only be used for their demented vanity projects, wasted in pointless displays of madness and excess, burned to fuel their enormous egos.

That's why it's just as important to support small, independent, local business as much as you possibly can. They don't have the resources of the megacorps, they won't be advertised as well, they won't be organized as well, they won't have the same services, they won't have as many choices, they may be less convenient, and they almost certainly won't be as cheap, but they actually deserve our money. They do pay tax (usually small business owners end up paying the most total tax compared to any group when you count both corporate and personal taxes) and will generally put it back into both their own business and the economy in meaningful and practical ways. If you want your country to be a better place, if you want actual economic progress, support small businesses.