Hi Francesco
From a statistical point of view, it's often quoted than aws - certified engineers have a 11% bigger paycheck for similar roles. (I could search back for the source, but Google should bring you similar stories). In my experience, I can't really tell if the flow of job requests is higher now than before (in Montréal we're quite lucky that there's much more demand than offer, so recruiters reach out on a daily basis).
Like anything else, a certification is not a on-off switch that turns everything from black to white, it's probably much more subtle than that. But that's true than in some recent discussions I had, the fact I am certified moved the discussion to other topics quite fast, people acknowledge it and seem to value it. But this is only a small sample ;-) (Similarly, we recently hired an engineer, and having a cert was definitely a plus for this role... I wasn't involved in the salary discussion in his case, but that could only help)