Why are products like OpenBCI modules on eBay & Aliexpress as well as BEATS not tested & reviewed as intensively as single board computers on YouTube?

Products based on the ADS1299 from China leave us often insecure. Since we have hardly any tests of those, we do not really know how good they are. And Peter Gamma from www.petergamma.org is a physiologist and not a device tester. But he keeps on reviewing those products until he has found what he is …