In my state (OR) it takes 4 years to become licensed to do the work for others but homeowners can do the work themselves.
My experience is that it’s not generally well understood how simple it is to install mini splits. The supply companies won’t sell to you directly outside of d2c web companies like hvacdirect
My state has a program where they give you big rebates but only if you use some one on their list of approved installers and since there aren't many installers it creates a big backlog. Homeowners who could install them themselves miss out on the rebate.