It's not just googling
. It's communicating with others. In a no checks environment you can have an a la carte team of paid consultants and helpfull friends solving the test with you.
The way some teachers solved this was a 1:1 oral complementary exam, where students were asked to explain a random set of their solutions. This is drastically more difficult to cheat in real time, and you will almost certainly look like an idiot if you come unprepared. It's a stupidly simple solution, disincentivizing cheating through shame. Doesn't need any proctoring rootkits and rectal cameras, a simple identity check is enough.