Here's how to auto-delete cookies without an extension: https://github.com/arkenfox/user.js/blob/128.0/user.js#L669
Set privacy.sanitize.sanitizeOnShutdown
and privacy.clearOnShutdown_v2.cookiesAndStorage
(I don't know if privacy.clearOnShutdown.cookies
is still needed) to true
.
To allow a website to keep cookies do CTRL+I on the address bar then check "Set cookie" in the Permissions tab.
No one is going to read first hand what you are up to. It's just companies trying to automate pricing based on data they collect so they can up prices when you need something the most. That's just one simple example so you can understand but there are plenty of other things you can do with the collected data.
This is also important because they'll just straight up sell it to data brokers that'll aggregate it, make it searchable and sell access to it to just anybody. And even if you feel your are not an interesting target now you never know how it'll be in the futur, once the data is out you can't do much.