While Cambridge Dictionary defines "a practitioner" as "someone involved in a skilled job or activity", it seems to me it is hardly used outside the context of medical professions. Is that so indeed? May I refer to a community of, say, experts in data analytics as "data analytics practitioners"?
I once gave a talk at an academic conference on public administration. Unlike everyone else there, who were all academics who wrote about public administration but did not do it, I was at the time a 'practitioner' of public administration. When I was thanked for my talk, they said it was good to hear, for once, from a 'practitioner'.
So the word is by no means confined to medicine - and no 'strictly speaking' about it. But the word demands a context: you can't just be a practitioner; you have to have a speciality (or specialty) that you practice.
One can apparently be a practitioner of change and the composer Maurice Ravel must have been (tongue-in-cheek) a practitioner of the dark arts, according to one author. You can also be a practitioner of educational leadership, a practitioner of crime prevention, or a practitioner of low-carbon education.
CPAs (Certified Public Accountants) can be practitioners too and, in Canada, you can get a permit to be a practitioner of foreign law. You can even take a college course to become a practitioner of feminist activism.
I do think that it is most often seen used for practitioners of various healing arts, but I don't see any reason why you can't talk about data analytics practitioners.
I've seen it in works of fiction applied to people who practice magic. A person practices law as well, but we don't say they are legal practitioners.
I've seen the terms "Software assurance practitioner" and "Safety assurance practitioner" used in internal documents at work to describe the class of people performing those functions. It was a sample of bureaucratise rather than regular English, but "data analytics practitioner" would have been perfectly natural in that context.
From my specific experience, the term "Childcare practitioner" is common.