As others have said the defacto condition is that the vast majority of frames come from the far east; typically the better end from Taiwan and the cheaper stuff China. Some manufacturing concerns are owned by the actual brands, many are independent and manufacture under contract / commission. The brands' input ranging anywhere from designing the frame from the ground up and speccing every detail to selecting a pre-designed frame off the shelf and slapping thier branding on it.
Brands may well select different manufacturing facilities for different quality products at different price points, so just because a company's top-end stuff is fantastic doesn't mean this can be applied to its mid or entry-level bikes, and vice-versa. Same with date of manufacture too; just because last year's model X is great doesn't mean this year's will be too.
Like most consumer product markets the bike world is run on bullshit - the marketing man is king and perception reigns supreme over substance. Many, many bikes are sold off the back of utterly false, misleading, nebulous claims about their facets (country of manufacture being one amongst many). Most "reviewers" will have an agenda that renders them far from objective, so beware when buying.
Be very cautious of any brands owned by investment groups / vulture capitalists - their MO is usually to slash production costs and inflate prices; continuing to sell increasingly sub-par products to unwary consumers off the back of misplaced brand loyalty / faith and more marketing rubbish.
Be aware that as the world's economies continue to circle the drain and wealth disparity grows, manufacturers are increasingly desperate to exploit the filthy rich, with eye-wateringly expensive products that offer very little value in terms of cost of production versus retail price.
While conceptually the bike has changed little in a hundred years brands increasingly rely on fabricating change and arbirtrary performance goals while shortening product life to keep consumers buying - so be aware that "the next big thing" might not be the revelation it was sold to you as, the real-world difference performance between old and new / cheap and expensive bikes is often far less than implied, and that new tech often hides many disadvantages behind the benefits it claims to bring.
Despite liberal coatings of marketing rubbish product quality control (especially on composite frames) seems to leave a lot ot be desired, but unless you're buying right at the top end of the market from one of the few who actually manufacturer in-house you're unlikely to be able to identify which these are or how to avoid them.
Basically, just like most other walks of life nothing's as it seems, most people are out to screw you for their own personal gain and it pays to trust nobody, do your own research and come to your own conclusions.
Personally I find all of this hugely stressful / demoralising so seek to minimise my exposure to this crappy state of affairs by buying a bike that should last me a lifetime - A glorious steel ride from British company Genesis; made from thoroughly British Reynolds steel tube (and manufactured in Taiwan for a brand that's owned by the dubious-sounding "H Young Holdings"
).
Basically unless you're paying thousands for a custom-build by a local bloke in a shed you're unlikely to ever know much about the origins of your frame, the people who made it, the ethics involved, the manufacturing standards adhered to, the value for money you've received or whose pockets your lining...