Providing your own materials isn't really a unique thing. There's a lot of blue-collar jobs that require you to bring your own tools to the job. When I applied for a construction job back as a teenager it was a requirement that you bring your own tool belt, hammer, hard-hat etc. My girl-friend's ex bought $100,000 worth of CNC equipment for his first job. My grandfather owned his own bulldozer and while he was an employee of the company he rented the dozer to his employer. I know mechanics that own and bring their own tools into the shop.

Even today, I provide my own laptop, desktop, and work environment (I work remote). If you are particular and a specialist in the tools that you use then it makes sense to bring them with onto the job.

Yes, according to the current definitions (maybe, or maybe not, see below). However, the point is that instead of making up a new category, which means you are mucking with definitions, you can just as easily change the definitions to clarify that these are, in fact, employees.

I bring my own laptop and my employer has a "work anywhere anytime" policy (as long as you get your job done). Does that mean I am no longer an employee??