It is my view that, in many cases, it boils down to choices. Some people have an aptitude for mechanical things, and are good at what they do, while for others, there skillset lies somewhere else, and they don't want to go through the learning curve it requires to accomplish what needs being done in a professional way.
Sure you can Google how to use a chainsaw, but having used one for a great many years, I wouldn't recommend it. Every situation is unique, and it takes a good deal of experience to avoid the dangers. It's often makes more sense to do what you're good at to make the money to pay someone else to do something you not good at.
.... and btw, not everyone who writes directions included with products should be doing so. Some have their head in their nether regions, and not everything on youtube is put there by people who are authorities. JMO