However, you argue that restricting free trade further and eschewing the benefits of comparative advantage would be an improvement
I am only stating the mess we're in, not making any suggestions about whether to keep 'free trade.' (Take another look at the OP.) What I want to do is to improve people's understanding of the real situation, and to reduce their reliance on information fed by the conventional media, etc.
because we don't really have truly free trade anyway. That logic seems broken to me. Wouldn't it be better to move in the direction of free trade instead?
The only way to 'move in the direction of free trade' is to have a free monetary and financial market. But, don't hold your breath, since the political and financial elites are not about to give up their power, until enough people become aware. Probably not in our lifetime.
People "jump to the rescue of free trade" because it is what "rules best for humanity". Restricting free trade benefits only a few people at the expense of everyone else. In the Trump case, tariffs on steel will help U.S. steel companies at the expense of everyone else in the U.S.
I'm not arguing for Trump's policy. But we have to understand that his proposals (and indeed he himself) are a long-term side effect of the global financial manipulations by the elites. If we keep the status quo, the same global imbalances will just continue, and will blow up in our face in a form perhaps even worse than Trump policies. The only difference is that today's elites will continue their good life for a while longer, if we keep things the same. (And that's why they're so scared of Trump.)
As I wrote, the cancer has spread, and at this point we're looking at pain no matter what we do. The only good thing I can say is that, with higher public awareness, hopefully, in the long term, we can reduce the ability of the elites to manipulate money and cause these painful imbalances in the future.