Again not trying to start an argument, but it seems there is some confusion about what is legally required.If you are not an electrician and not on a competant persons scheme then all your work would have to be inspected at your cost which I believe would be prohibitive, so the competant persons schemes are forced upon you. There are a lot of electricians that are time served and fully qualified that look at the domestic installer as just DIY'ers because they do lack that understanding you gain through academia.
Inspected by whom and to what end? Most professional domestic electricians call these scheme's, Scams and try to avoid them, indeed most I know have resigned from them after paying the exorbitant fees for a number of years for no benefit.
An electrician does not have to be a member of a competent persons scheme to offer their services, they just have to be competent.
There is no such thing as a fully qualified domestic electrician, there is no legislation or professional body that an electrician can be a member of and no legally binding regulations that they must follow, only the made up out of thin air "EIT Regulations" which have not been legislated, passed through Government, given Royal assent or passed into law by the Secretary of State.
Some of the awful electrical work/practice's I have seen will not change until there is a recognised professional body responsible for the standards required and not the convenient made up ones that appear out of thin air to jump on the bandwagon of the miss-placed competence scheme's.
The additional problem (my own Association/Institute included) is the agenda of the Board to increase membership above all else, I have first hand knowledge of this.