So non-zabiha meat is not halal and same as KFC and Mcdonald's?
Not entirely, You can eat slaughtered animals from people of the book. However, good luck trying to find a christian or a jewish owned abbatoir or slaugher house these days.
I've worked in the meat industry, and this is something which does not exist anymore like it used to in the time of the Prophet pbuh.
If you do happen to find a jewish for example farm, good luck tyring to purchase it as kosher is twice as expensive as halal meat.