My perspective is that this just takes time, because it's necessary for people making hiring decisions to have personal experience and knowledge with the material. Very similarly to how people who went to some college project their opinion (good or bad) about the program at that college onto other people who went there. I've done some hiring, and I've taken lots of online courses, and if I see a certification for one that I have taken and thought highly of, then it absolutely means something to me. But I'll definitely ask a bunch of questions to get a sense of how well you learned the material.
Edit to add: I think I left this too implicit: my main point is that as these courses become more prevalent, there will be more people with personal familiarity in higher positions, and that will make them more valuable.
Edit to add: I think I left this too implicit: my main point is that as these courses become more prevalent, there will be more people with personal familiarity in higher positions, and that will make them more valuable.