These are not examples of multi million dollar businesses that offer real career progression. None of them are remotely big enough for that. Scale is needed for the right proportion of chiefs to indians.
You are blinded by your bias. I am not being derogatory to PTs, I think it is a tremendously hard job to do well and most people will never appreciate that, but you've not shown me a single business here that could offer long term career progression for a group of ambitious young men as they develop within their profession.
Other industries take their young talent and nurture it, allowing room to grow whilst still using many of the skills and insights picked up along the way. That's very rare in PT because the business is still too much every man for himself and / or small businesses. I do think it will happen, but it needs the right sort of businesses in it in order to offer the right long term opportunities.
Not much room for growth in PT at big box gyms...sure
But...i met my future boss 15 yrs ago personal training. It is a GREAT way to network, if you can do it right. He saw i was a hard worker and i asked him for a job. im a Director at a large recycling company now.
Other route: learn the fitness business, open a gym or be a GM. Research " Thomas Plummer" and fo to one of his seminars. Or get his book, its called someing about making money in the fitness business.
Ive been there...23, PT and not sure what to do. Difference is that I have a Big Ten college degree to "fall bakc" on. Regardless, those are my suggestions
Side note: I would go back and get my NSCA CSCS ( or something like that - strength conditioning specialist) and do what "coach" does and train athletes.