This. No one knows for sure, so the former is possibly true. The latter is demonstrably true.
No this is not binary. Just because you get coaching doesnt mean you will be able to execute on that coaching. Not because you are ignoring it but because you have not developed the skills or abilities to process it yet.
Fields has always been slow to throw even when coached by one of the best in college ie Ryan Day. That was always something he would have to improve on in the NFL.