At the end of the day these companies facilitate the connection between a producer and consume and then take a cut ( albeit a large one ) for the connection. I just don't see how these companies owe more than the contract specifies.
It implies capital controls - you can't send big piles of money abroad, but you can spend freely domestically. You can't hire foreign labor and if you want to import good that have a large foreign laybor component well there are going to have to be tariffs, tariffs high enough that you will decide to make things domestically instead. In other words the tariffs are not designed to increase tax revenues for government re-distribution, they are designed to restrict trade by being high enough few would choose the pay them, but still allow goods and services into the country that cannot be sourced locally at least not in the short term.
It requires tight restrictions on immigration, because communities will need to absorb and integrate new members. A solution like a large immigration tax would probably be in order. Want to stay in the US more than few weeks $50K! Want to be on the citizenship/green card tack $80K!
I think what you're talking about is the effects of globalization on the cost of labor. From that perspective Fiverr is different in that it is a global "gig economy" company and the buyer gets to choose between everyone on earth and not just their local neighborhood. In that way I would agree elected leaders could have an affect and, I would say, are obligated to protect their constituents. However, globalization is a very different discussion and has impacts far beyond just the gig economy in the US.