How can you tell as a recruiter if a resume is good? People can put anything on it. Did I work with SAP 20 years ago? Yes, for two weeks! And I can simply put that on my CV. Candidates do that with every piece of technology.
Ok, how to test this then, that they actually master the technology?
Real interview of 2h with maybe a coding challenge. "This does not respect my time and anyway I cannot code under stress" will some people complain.
OK, then maybe some automated offline/online task? "Why do I need to solve some algorithmic nonsense without ever speaking to a person? They don't respect me as a person"
Hm ok, then maybe a real interview in house. But with how many candidates when I get 100+ applications for a position. I CANNOT talk to all of them...
So in the end it's again statistics... Filter out those where the probability is high that they are fast learners and dedicated. What is a good indicator of this? Well, high school and uni grades....