The moat is the difference between knowledge and know-how.

You can read all the plumbing books, but you need to get your hands dirty a few times, mess it up and fix it, to get mentally comfortable and efficient with the work

Yep. I can do basic plumbing, but I haven't touched it since I started making enough money to pay a plumber to do it for me. Plumbers are worth every dollar they charge if it means I don't have to spend two hours under a sink cursing at rusty bolts.

"Professional plumbers can't stop that. The real moat is that most people don't have time, don't want to buy tools, and don't want to get shit on their hands."

"don't want to buy tools, and don't want to get shit on their hands"

Thats closer to the truth. The rest of your post is fluff. Its pure economics, not rocket science.