Question: what are the chances of being a professional goalkeeper?
Answer: Most teams recruit 2 or 3 out of 22 players. Multiply that by professional teams, that can pay a decent wage, in the world (I don't know but let's say 1000) and that is maybe 2–3000 jobs available. The best keepers I have ever played with in my life never made it pro. And trust me they were exceptional.