Just to remind people, most sane countries do this for soft power. You want influence and dependency on your markets, it's way way better than whatever short term gain you get from taxing you own people for imports.

Same for USAID, it's in all competing countries to fill that void and gain that goodwill since it also makes you safer and less prone to terrorism or influx of migrants at your doorstep.

Edit, I should add China is one of the more aggressive tarrif countries on developed countries, but even that's stuff like 6%, not fucking 30%+, plus they have more strategic reason to do so.