Cookies are very small snippets of code that have a specific purpose. Making a one-size-fits-all cookie would make them complicated and much harder to track - which goes against the point of a cookie. Also, cookies are often independent of each other because they are from different providers/different tools. Having a one-size-fits-all cookie would also present a security hazard and make laws similar to GDPR about cookie tracking difficult to implement. An example of a tool that actually does use one cookie is Adobe’s Marketo. You can read some more about them here. https://termly.io/resources/articles/types-of-internet-cookies/