The tech is in china
tech is not in china. most complicated electronic devices are developed outside of china.
manufacturing yes but not the cutting edge technologies.
anyone with enough money could hire developers to make a ASIC chip and start manufacturing miners.
at the beginning there was european, american, china and ukranian miner developers, few survided
it's right they buy their cheap from the same manufacters that amd and intel and nvidia buy their chip, which are all from a silicon factory, that are not in china, so they import that first, then they make the board, which is the easy part