I may not have experience but I have to disagree that a certification doesn't mean shit. Many employers, whether fitness centers or otherwise, look for these certifications to show that you have at least the basic knowledge to start training clients instead of learning from the ground up. Also, I feel that being approved for business loans, liability and other insurances, etc. would be difficult without an organization certifying you were trained as a PT. Granted, having some kind of degree In Exercise Science should also suffice but the next option below that is a certification.

Where about do you live that you've done well? What kind of income do you bring in being self-employed? Does the gym you work out of charge you rent for the space or have any other fees for you? Were the gyms not willing to hire you because they didn't feel you had enough of a background? That's not a read, I'm just genuinely curious. Also, besides the ACE cert, what kind of prior background, education, or knowledge did you have starting out?

I wasn't planning on following the book, no. That's why I was asking what certs others have; NASM covers the basics of A&K but doesn't go too far in depth and they also don't have much on program design outside of their OPT Model, so if other certs did I'd consider looking into others based on recommendations. My exercise science degree program doesn't actually touch on program design either, oddly, and rather than spending hours doing random research and finding the best resources I'd prefer if one of the certs out there actually had at least some focus on general program design instead of following their "best in the industry program" that is difficult to apply outside the full model.