These businesses are underground because the regulatory burden of being over the table makes them either impossible to start because of upfront costs vs future

These businesses are underground because the regulatory burden of being over the table makes them either impossible to start because of upfront costs vs future profit or impossible to to keep viable because of recurring costs. Nobody "wants" to run an under the table business and have their income be subject to the whims of enforcement but the other option is just so bad it's the lesser evil.