Imagine this case now:
I own a small company, Foo & Sons. I invent a new form of widget, that's 10% more efficient than other widgets. I can patent my new widget, and now I have exclusive right to manufacture these widgets in my factory for $1 a piece, selling them for $2 a piece.
Now, a big company, Widgets'R'Us, is capable of manufacturing these widgets for $0.50 each, as they have economies of scale. Without patent protection, they could make my widgets, and sell them for $1.50 each, putting me out of business. However, because of the patent, they'd have to pay me a fee if they wanted to make my widgets. I can now decide whether or not these royalties are more valuable tham making and selling widgets from my factory.
I think there is a stronger case for patents for processes that can be easily replicated, reverse engineered, and made profitably at scale (this is a key factor IMO), like lightbulbs or batteries or something. Even then though, I think there are cases to be made that patents still may not provide benefit. For example, why do people still buy Advil or Tylenol over a generic brand, is it perhaps trust in the brand and confidence in the purity and safety of the product?