They generally don't, because you don't need banners to store cookies that you need to store to have a working site.
In other words, if you see cookie banner, somebody is asking to store/track stuff about you that's not really needed.
Cookie banners were invented by the market as a loophole to continue dark patterns and bad practices. EU is catching flak because its extremely hard to legislate against explicit bad actors abusing loopholes in new technology.
But yeah, blame EU.
And before you go all "but my analytics is needed to get 1% more conversion on my webshop": if you have to convince me to buy your product by making the BUY button 10% larger and pulsate rainbow colors because your A/B test told you so, I will happily include that in the category "dark patterns".