In the old days, when an importer purchased Chinese goods in bulk and resold them, import checks were commonplace.... AND the importer was legally responsible for paying import duties and selling goods to the public that were legal and met safety standards.
Now that any individual can order direct from China (with cheap subsidised postage!), the floodgates of untaxed and dangerous shite are open.
One solution is to address the subsidised postage that makes this state of affairs possible.
The old system of spot inspections worked because most import volume was from known, repeat importers.
In my country the government is pushing those companies to have local warehouses. So if items are bulk imported by the marketplace, in theory it should be easier to inspect.