Generally no
It gets more complicated in the US because of unions. In many places, you can’t become a plumber or electrician without an apprenticeship, which is controlled by the trade unions. Therefore, community colleges might offer classes on plumbing or electrical, but there’s no equivalent to a certification program, because it’s not possible to become a professional just by going to school.
This source [0] says “non-dentists cannot set up or buy dental practices as an individual or partnership but they are permitted to be shareholders of a limited company which owns the practice” and “the majority of directors of that limited company cannot be non-dentists”.
[0]: https://www.plutopartners.co.uk/post/who-can-own-a-dental-bu...
That said, this isn't what most people are talking about when they are talking about starting a business.
Socially, I’d say that it is respected and regarded as a sign of dedication to ones interests.
Where do you need a degree to open a business?
So getting these qualifications are required for reskilling.
Daycare center, hairstyling and financial advisor are others that require qualifications / lic
People aren't learning these professions at folk high school are they?
So you really need education that leads to recognised qualifications.
Reality is most people wanting to retrain are going to do it as a single person business as a plumber, hair dresser or similar.