To have it set in the browser is quite detrimental to online privacy. Legitimate interest is an attempt to circumvent the law. It is not like your browser is sentient and could recognize that.
Also I said this in the context of GPs statement in that legitimate interest couldn't be handled. So it without saying it goes alongside a general advertisement cookie rejection.
> If the "browser" did this for me I wouldn't know what absolute illegal nonsense they would try to sneak in via "legitimate interest".
Of course you would, if it's done properly. The browser would be able to list the cookies too, but in this case in one consistent UI that wasn't built with malicious intent.
Which is also a huge cost. As you say, users want a "no and never ask me again". Well, you can have that today. Just don't do anything that requires anyone to say no.
And again, if a site chooses that path then the banner is a feature. It is disrespectful and although it is a royal pain it is very good for users to know up front what kind of entity they are dealing with. Remove that and people will become apathetic to it.
In that case, starting to go after big corps that abuse legitimate interest with GDPR fines should sort the problem out pretty quickly
Youtube was drastically improved recently (due to fines), for example.