How is that a non-solution? It should be very hard to introduce cookie bloat. Preferences can and should generally be stored server-side. I can't stand it when I lose settings on an account simply because my cookies are on another machine.

Adding cookie data should be a big deal because if everything in the cookie is important valid reasons for needing more data (or less data) imply major architectural changes.

For example, after a merger in which two company websites should be integrated you might start with one simple cookie, transition quickly to two independent cookies on two domains, then use a cookie with two keys when the two sites have separate backends but the same domain, then eventually a cookie with a single key again after extensive replacements and reimplementations.