Most hobbyst (at least where I live) order directly from China on ebay or aliexpress. It's cheapest this way.

Customs services worldwide probably won't even come close to inspecting even 1% of that unending stream of tiny plastic envelopes containing some sort of electronics heading for thousands of local hobbyists. It's a logistical impossibility.

They could blacklist everything and only pass-through stuff sent by trusted exporters I guess. Check 1% of the packages, if some exporter lied revoke his trusted status.

But I highly doubt they will do it :)

That's what I do it almost all my equipment (not US, though)