I can't turn my hobby/side gig into a small business without navigating a bunch of bureaucracy to obtain 9001 permits, some of which are inevitable "may issue". Assuming I made it through that I'd be subject to all sorts of government oversight to the point where I either have to sink all the resources I would spend growing my business on compliance or just not think about it and hope that by the time anyone notices my business is big enough to afford the cost of compliance. For programmers, lawyers and other occupations that don't deal with physical things the issue isn't as big but for blue collar businesses this is a big deal. You literally cannot hope to comply with everything when you're in the boostrap phase and that dissuades a lot of people from striking out on their own.
The fundamental problem here is that laws and regulations written to deter some mega-corp from systemically being sleazy to make a buck apply equally to small businesses. turns out it's only the mega-corps that have the economics of scale to make compliance possible while still making a profit.