Since A-levels are kind of trivial compared to undergrad work, and very trivial compared to postgrad work, in relative terms no. Given they're also fairly irrelevant to any practical use outside of academic, it's also not much of an indicator of "intelligence" in a work-based environment either.
A-levels are not an end in themselves. They are a means to an end - what that end varies between people, but in general it's "working in x area" which, if you're taking A-levels, usually also requires one or several degrees as a further means to that end.