I have a PhD. A PhD is just a certification that you have depth and breadth around a topic at an expert level. An expert of a topic is someone who has the skills and knowledge to evaluate someone else's work on the topic, and who can themselves do novel work on that topic or nearby.
As with all certifications from dog-training to fighter jet pilot, PhD certifications have both false positives and false negatives. Meaning, it is entirely possible to get expert levels on a topic without getting the PhD certificate. But the reason people insist that you get a PhD is because they don't want to get into the whole argument of whether you really are an expert. Otherwise, there is no reason to get a PhD. If you can convince people that you are indeed an expert without the PhD certificate, good for you. If not, sucks to be you.
As with all certifications from dog-training to fighter jet pilot, PhD certifications have both false positives and false negatives. Meaning, it is entirely possible to get expert levels on a topic without getting the PhD certificate. But the reason people insist that you get a PhD is because they don't want to get into the whole argument of whether you really are an expert. Otherwise, there is no reason to get a PhD. If you can convince people that you are indeed an expert without the PhD certificate, good for you. If not, sucks to be you.