Two points...
First, there does not seem to be a consensus that U.S. standards of living are improving.
LINK
A more complete - and, perhaps, more cogent article appears
HERE
Now you mention that tariffs or other trade barriers are a form of tax. That certainly seems reasonable. But if we suppose a (government) revenue-neutral mix of taxes, might tariffs be better than some other taxes? For example, if tariffs were high, but income taxes were lowered, would that promote American growth better than does the current mix?
I certainly don't claim to know. But it seems an interesting speculation.