I respectfully believe that there is no need for cookies from sites to tell other sites what you've been looking at or to follow you and suggest with ads to buy something.  You can't selectively remove cookies in any browser that I know of, so clearing cookies that way removes all of them.  Meaning I'd have to log into newagtalk.com each time too.  If my credit card or bank put cookies on my computer I don't trust that somebody might utilize that information in a way I wouldn't like.

I also have an ad blocker because some sites have gone completely nuts with ads.  For example this site https://partners.titantv.com/default.aspx had over 100 ads blocked.  If sites were reasonable  and ran one or two ads it would be different but some almost cover all the information with ads or take forever to load as they are busy loading ads.

I don't know the downside of deleting cookies.