Well, it's ok for some, but I bet you can' t do 4 thou track and spacing and 10 thou vias....
And how do you register top and bottom layers?
And as for mutilayers - that's tricky.
The CNC is only used for crude single layer things. The power stuff you do on strip board.
I started with rolls of 0.5-1mm wide etch resistant tape and an etch resistant drawing pen.
Then etch resistant rub-on transfers (pads and tracks).
Then moved to spray-on photoresist. Messy, smelly (has to be baked on), oneven, dust in it, etc.
Then the pre-fab photo sensitive boards. Then the iron-on transfer sheets (bad).
I think I produced the best boards with etch resistant transfers. I think it was "Letraset".
Not sure if you still can get that (I'm talking 30+ years ago).
...professionally made boards are so good and cheap I woudn't bother these days.
And maybe the slow boat is partially a good thing - it makes you check thoroughly before ordering..
When your design skill improve, it's indeed the only way.