Because it would be harder, there are 2 types of cookies: essential ones, necessary for the site to work correctly (remember login, preferences and a bunch of other things) and there are other cookies that are not necessary, and there is no real way to add this distinction since the browser doesn't really have any way to understand which are which; Also, before anyone reply "but if i don't want to remember my login?" Some sites still write temporary cookies to work

You can also see what cookies are wrote on your device with Developer tools but this is not a viable way for normal users and the cookies will tell you little sometimes