well the tree cutter I know started in forestry, then a city company doing routine care. He combined the two and now does ‘problem trees’. A problem tree can cost up to $3000 to fix and up to $7k to remove.
The carpet cleaner I know pulls a thousand a day solo. He works for himself, high end decorators, realtors and charter aviators book him a month out.
my point is get really good at something and your ability becomes the other guys barrier.
These are business owners not pure trades people.... Yeah I know a guy with a corner store or whatever other business that makes coin... so work in a corner store??? They are making that money for business sense not just because they have a specific well paying trade. Anyone can open up a similar business as there is no real barrier to entry, entrepreneurial skills more than trade skills is the difference in your examples. If they hire people they will not pay them well as they do not need to (no barrier in both examples).... This is very rare case and the vast majority of the people taking up carpet cleaning as a "trade" will make min wage. Tree guys a little more, Amazon money as the main barrier is working from heights.
Real world example, we had our trees trimmed two years ago. Regular size red norway (about 2.5 feet across at the trunk) in the front and a large silver maple in the rear (just short of 6 feet across at the trunk with no heavy equipment access). Five guy crew (rotating through being in the trees) and NO WAY a one guy on his own or even a two man crew couold do the job! They were here 10 hours total for $2500 before tax... but that is not $200+ an hour in wages! Acknowledging the 10 hours and $2500 price was a little lower than usual for the size of the job (maybe your 3K if they took all the wood away) as I had them leave anything larger than 2" across (fire wood for me), multiple cords, again just a trim not removal... On top of the five guys was an arborist assessment that they have on staff. They had full insurance and WSIB which is high for tree services. The business owners make their money.... The guys in the trees doing the actual work (the trades) could make the same or more money working in an Amazon warehouse. And BTW, it does not need it but we got a quote for removal of the silver maple just for future budgeting, yes 10K.... but now there are large cranes, possibly multiple days and a much larger crew all making Amazon warehouse money.
Electrician, plumber, etc. make pretty good money even as employees because of the barrier to entry and the requirement to have a license. An employer can't just hire a random guy off the street like carpet cleaning. Yes, they make even more as a business owner (but now they are entrepreneurs) or as a single proprietor (both owner and trade).
Most people regardless of education or trade do not have the skills to be a good entrepreneur. That is one of the reasons so many small businesses fail. A person can be the best skilled trades person in the world if they have no business skills they will fail on their own. A very small percentage of people will be good natural entrepreneurs and will make big money because of that (not the trade or degree or whatever itself), so it is silly to label their success as being in an unlicensed trade.
The majority in trades will also make good money even as employees, the higher the barrier to entry (with noted exceptions like mechanics) the higher the money. At best in your examples the entrepreneurial skills were the barrier to entry for being the business owner, not their specific trade (they would have had similar success without the unlicensed trade).