Actually, in most cases the testing is done by independent test labs. But the testing is paid for by the manufacturers, not ICC. The test reports are given to ICC, who apply the test results into their reports. Then the lawsuit comes down to ICC claiming no one else can use these test reports...
IAPMO UES was drafted by the industry to be an alternative to ICCES, who had a monopoly on product evaluation reports in the USA. In most other countries, a government agency serves this function. ICCES abused its position & failed to serve building departments, engineers, etc., with timely...