Yes, the barrier here is the desire to study and pass the exam. If willing, you are up and running relatively quickly - but only as a technician under someone else's operating license. To get the operator license (eg to be a full on pest control company) requires 2+ year documented experience and another set of exams.

The operating license holder is also on the hook for legal action if (when) things go wrong.

"Control" is interesting and I have found in all trades that people value their freedom. The good companies don't monitor employees too tightly, and are rewarded with loyalty and longer tenures generally. Of course you have to run a good recruitment and referral process to find the good people!