and yet... Marketing is super important. If you've got a good idea, people need to know that it's there, or else that idea won't exist for much longer.
There's a product that I knew about, and it was essentially a sprinkler system you fitted to your home radiator. The idea being that if the room got to a certain temperature (like, say, when the room is on fire), the water inside the radiator would get too hot and burst out of this little plastic thing on the end of the radiator as steam, dousing the fire. It wasn't there to save lives of people in the room, because the room would have to be so hot that everyone inside would be dead, but it would stop the fire spreading to the next room.
They had lots of tests done, video evidence of it working, but nobody would buy it because they insisted on doing all the marketing themselves, and they were shit at it. The guy who invented it spent more time arguing in comment sections than actually advertising the product. If they'd hired a marketing firm to actually sell the product, they might have been able to sell it to more than a single council's social housing stock. A lot of investor money went down the drain because of that project and because the ego of the inventor couldn't be kept in check.
Kim Jong Un is batshit crazy, but he does know the extent of his power. His power doesn't reach much further than North Korea itself, and if he tries anything that might piss off China, he backs off. Trump has no such restrictions, he can do whatever the hell he wants, and does.
The general principle in international relations for the past 100 years is that if you kill your own people, nobody really gives a shit. If you start killing other people, well then that's when other countries start taking notice.