Firefox 85 will be released in January with a new feature called Network Partitioning to protect against tracking
The option is based on Client-Side StoragePartitioning is a new standard being developed by members of the World Wide Web Consortium. As a specialist explained to ZDNet, the browser can save data from websites in many different ways, not just through cookies. Other storage mechanisms include HTTP cache, images, icons, fonts, etc. All of this can be used to track users.
All of these storage systems are sharedfor websites. This allows one site to determine the loading of resources from another site. With Network Partitioning, the Firefox browser can save cache, icons, CSS files, etc. for each site separately. This will make it harder for third parties to track users.