The biggest problem with modern capitalism is that you don't know if something is "good" before you buy it. The information asymmetry / obfuscation ensures that.
Information asymmetry and lack of regulation allow bad businesses to stay in business. I’m sure you can recall quite a few if you sit down for a minute.
Also poverty (lack of options). Think of how the 70% of the population who barely gets by would read your comment on being cheap.
Of course it is also up to you. You can always choose to buy from dodgy sellers to save a few bucks.
Brands exist for a reason, to guarantee a certain quality.