I have some open questions, though this is more implementation than concept - what categories of software would need what licensing? Is there a delineation for platforms with more or less effective sandboxing, e.g., mobile vs desktop platforms? Do we need licensing for non-mission-critical software like game development (not a trivial question given multiplayer transmits and parses data)? Memory-safe versus memory-unsafe languages?
Now, I can think of some good situations that should maybe require formal licensing, e.g., cryptography, though how to delineate that could be tricky. Certainly I would want someone building a cryptographic vault or library to have very good knowledge of cryptography - I am not sure this is needed if you are effectively dispatching to a known good library, but it is still possible to build highly insecure protocols on top of it. Wondering if I would want a single large license, or some kind of specialty licenses for such cases, though.
My biggest gripe though, is that I feel most of the problems of software come from companies behaving irresponsibly - collecting too much data, rushing features through, pushing top-down control and schedules making it difficult for engineers to push back for needs and to build systems effectively. A lot of corporations pretty much give marching orders to their engineers. Maybe if software engineers were licensed, and there was personal liability against one's license to disobey, it would create a strong incentive to not implement such systems. I have my doubts this would get implemented in the USA though, as we have already unfortunately mostly stood against regulations like the GDPR. Maybe the EU would do this - but I am not sure if it is a better strategy, if that is the intent, versus focusing the state on attacking companies with malicious intent and sending them directly out of business.