But then there is even less point in buying the branded mix rather than individual ingredients that you can use for various recipes with ratios that you like.

The point is that I can make brownies, rolls, whatever I please without having a cupboard full of all kinds of crap like flour, sugar, cocoa etc that attracts bugs and expires and so on.

I buy one bag that's dirt cheap and has everything I need including instructions. And it just has the same stuff I would be using anyway so there's no downside. No scary ingredients. Just freshly baked goods on demand.