It’s not a “middleman rent seeking”, it’s protectionism. If lower cost production is available elsewhere in the world, there are three options.

1. Stop producing locally. Allow the market to take care of it.

2. Deregulate minimum wages to allow local businesses to price locally produced goods competitively.

3. Impose a tariff on incoming goods to protect local producers.

Which is your preference?

Where is the rentseeking in that example? Rentseeking is the expenditure of resources to influence the rules so you can charge rent. The sock merchant in the example isn’t.