Other countries wouldn't get a permanent 125% advantage over the U.S. They have zero involvement with the tariff because it's the importer who pays it to the U.S. Treasury when the cargo arrives in the U.S. In the case where it's a single-source, IP-protected item, the tariff is largely irrelevant to the country that produces it. People will buy it if it's a necessary item. The tariff doesn't give them a reason to adjust the price up or down or do anything different at all. They sell to their U.S. wholesale customer at the same price, that wholesale customer pays the tariff, and then the wholesale customer either passes the tariff through to the retail customer or charges multiples to maintain the same profit margin percentage.
In the absence of IP protections, it would hurt the countries with the highest tariffs on their products because there would be an incentive to produce an equivalent product domestically or source it from another country whose products are taxed at a lower rate. In practice, it still doesn't work out to impose broad tariffs because no one has a fully domestic supply chain. It really only makes sense to tariff very specific items in new-ish markets where you have a foreign player whose government is subsidizing production, e.g. Chinese EV's, Chinese EV batteries, solar panels, etc.
What do you call necessary? What about non-necessary items? What about IP that improves manufacturing efficiency by 5% in some process? Better battery tech? Better UI? Better chips? Better sensors? In some cases the answer is yes, in some cases the answer is no. If the answer is yes then the US pays 125% more for that item, if the answer is no then the US has worse efficiency, worse prices, worse technologies.
You talk in absolute which makes me feel like you're missing all the nuances at play.
It's the buyers in the other countries who get the "125%" permanent advantage, not the sellers. Sure, it doesn't affect you if you're TCL making flat-panel displays. It affects you if you're buying flat-panel displays to incorporate into your product, by making your product a lot more expensive.
In the absence of IP protections, it would hurt the countries with the highest tariffs on their products because there would be an incentive to produce an equivalent product domestically or source it from another country whose products are taxed at a lower rate. In practice, it still doesn't work out to impose broad tariffs because no one has a fully domestic supply chain. It really only makes sense to tariff very specific items in new-ish markets where you have a foreign player whose government is subsidizing production, e.g. Chinese EV's, Chinese EV batteries, solar panels, etc.