I think you're leaving out some things and just mostly wrong and here's why.
There are so many things that get imported that we either do not have any current capacity to make here, or can not make for some reason like needing resources that don't exist here as much as in other countries, or being some type of food that no climate in the US is suitable to grow etc. So there will be no incentive to source such products here, or it will be impossible. Even in many cases where it is possible in theory, it won't happen. Like so many textiles are made in Bangladesh. Those workers are paid next to nothing, even the US state with the lowest minimum wage is orders of magnitude higher wages, the companies will still make the shirts in Bangladesh because even the 20% tarrif won't be enough to justify paying American workers to do it, to say nothing of the capital costs needed to build the factories here. Americans won't work for Bangladesh wages. So textiles will simply be more expensive under trump, by at least 20%, and inflation won't stop. This is just one example. Even if a company did start making textiles here and paying American workers, their labor costs would still demand that the price is much higher than we currently pay, and higher than what we have plus 20% as well. So, it's a retarded idea on multiple levels.
Regarding price controls, if the cost of making things is taken into consideration and only the profit margins reduced, I don't see why this won't just mean less profit margin and don't see any reason it intrinsically reduces quality. There's no law of the universe that says that profit margins must be exorbitant or capitalists won't bother. If you're worried about subsidy, I have terrible news. So many industries are ALREADY subsidized a ton. Like corn, beef, chicken, oil, and many many more. Socialism for the rich, fully supported by Republicans. And democrats too to a large extent I suppose.
I actually think tarrifs can be a useful tool for products where there is existing competition in the US, but it needs to be intelligently targeted. Doing a blanket 20% is dumb as hell and will be a huge system shock
Then theres the conversation about capitalism needing foreign workers with minimal rights to exploit for cheap labor and how they encourage repressive governments to keep those people disempowered so that they can protect their profits. This is why the rich fearmoneger about a one world government or one world unity. They fear workers around the world uniting. Why should a Bangladesh citizen's labor be worth any less than an American's? Aren't all men created equal? If workers all realized how governments and religion stoke fears of other nations and races and use this to divide people so they don't unite against the capital owning class, the jig would be up. Also, we wouldn't need to spend such huge numbers on the military to protect those corporate profits, which is what militaries and police largely do.
"I spent 33 years and four months in active military service and during that period I spent most of my time as a high class muscle man for Big Business, for Wall Street and the bankers. In short, I was a racketeer, a gangster for capitalism. I helped make Mexico and especially Tampico safe for American oil interests in 1914. I helped make Haiti and Cuba a decent place for the National City Bank boys to collect revenues in. I helped in the raping of half a dozen Central American republics for the benefit of Wall Street. I helped purify Nicaragua for the International Banking House of Brown Brothers in 1902-1912. I brought light to the Dominican Republic for the American sugar interests in 1916. I helped make Honduras right for the American fruit companies in 1903. In China in 1927 I helped see to it that Standard Oil went on its way unmolested. Looking back on it, I might have given Al Capone a few hints. The best he could do was to operate his racket in three districts. I operated on three continents."
-Smedly Butler, marine corps general
Turns out J D Vance's mother got health care assistance when Trump was president under Obamacare. J D Vance claimed that it was Trump who got his mother insured, but it was the ACA.
