1. During Covid, medical supplies were in short supply, to the point where the US government was flying in individual airplanes from China full of N95 masks and face shields. The guy making the video knew that Alabama (where he lives) wouldn't be on the priority list for where the masks and face shields would get distributed. His community's initial response was to 3D print face shields and donate them to healthcare facilities, but they knew that they had to step up to actual manufacturing to produce the face shields in necessary volumes. He was only able to find a single aging technician in Alabama capable of producing injection molding tooling, which he then was able to use to mass produce enough face shields to supply Alabama and neighboring states. If that one guy had chosen to retire before Covid, they would have not been able to make the injection mold locally. At a time where global supply chains were massively disrupted, they would have been screwed.
2. When an American company gets their products made overseas, the factory overseas that manufactures the product owns the tooling. This means that they're able to fill your order during the day, then at night make exact clones of your product with lower quality materials and undercut you, and you have no recourse. He brings up an example of a local small business that had this happen to them. Even though they had a design patent, they needed their lawyer to continually send letters to get Amazon to take down no-name clones of their product (and then the seller would just pick a new random set of 6 characters to sell it under). If US companies have no choice but to get their products made in countries that don't care about IP, then we're not just giving up on manufacturing, we're also giving up on designing products in the US.
When he was trying to get the injection mold for his grill scrubber made, lots of companies in the US were willing to do the actual plastic manufacturing in the US, but could only get the injection mold tooling done in China. He brought up that in the past, an American company would build a machine and then ship it away to the developing world to be operated there. We've now reversed this, so the high-skill portion of manufacturing is done overseas and the only Americans involved are just pushing the buttons to operate the machine.