Mass produced modern carbon bikes are formed in moulds. They are almost all made in factories in the Far East, and one factory might well make moulds and frames for a range of different bike brands. So far so what, we know this. And actually it doesn't make for bad frames, the skills and techniques built up over time to deliver consistent results across thousands of frames for big name brands means the only option is to be good. You can leverage huge economies of scale, and pay expensive riders, with huge exposure, to ride these frames, thus keeping the circle going round.
Obviously you can go down the bespoke route, or have a frame from different materials, like steel, which needs welding together. Welding can, in theory, be done anywhere. Bespoke is becoming more popular, as an antidote to brand dominance by big firms, and that's good as well. Anything which encourages bike buying is, in theory, good in my book.
However, it's time to start asking questions when new brands arrive in the market making strenuous claims about bespoke, high-end, designer and so on and so on. And it then turns out their frames are made in the same mould as every other bike that comes out of that particular factory. (I'm looking at you Dassi) It does not, at all, mean that you will have a bad bike, far from it in fact. It is much more complex than that.