This would seem to be an admission that the domestic product is inferior, otherwise why would it be necessary to burden the import with tariffs?

In any case, if that's the intent, it's not working out for fairly predictable reasons. Lots of imported goods have no domestic equivalent. The factories required to make them require years of investment, which is not forthcoming, because the longevity of these tariffs is highly dubious and the government is doing nothing to encourage business development. And even if there were new factories, they would have to import machines and raw materials, which are of course tariffed, driving up the cost of domestic goods, and defeating the alleged purpose of the tariffs.

There's no just explanation that can make the tariffs look useful to anyone. Like everything from this administration, it's about the appearance of action.