Beware the "guy" who knows it all and can do it all. A "self professed expert" professes to know the most, but most often knows the least. It is the quiet one who often seems to be the most knowledgable and skillful.
Over the past 35 years I have hired and worked with hundreds if not thousands of tradespeople. Of those, there are really just a handful in all of the trades who I would rate, "top notch". I have interviewed many workers and subcontractors. I don't think that I have ever interviewed a carpenter who did not profess to know how to do it all and profess to do quality work. Of those hundreds and hundreds, I can only think of a handful of people who really were knowledgeable and skillful tradesmen, and who actually did quality work.
Every company that I have ever heard of does "quality work". I have never heard of a company that advertised that they did poor quality work. In 35 years of building and remodeling, I have seen a lot of work done by unskilled and uncaring tradespeople. As an example; of all the kitchen stove vents that we have had to work on or change for a kitchen or bath fan as part of a remodel, I can only think of a couple of kitchen stove vents that actually worked. In our last kitchen remodel, the back draft flapper in the fan would not open to let the air vent out because the duct was bent so the duct covers in the cabinet would fit: not that the air needed to be exhausted. It had been that way since the house was built 12 years ago by Cam West, now Toll Brothers.