Is it wise to whitelist OR allow many sites storing cookies?

When You enable removal of all cookies upon web browser restart, is it wise to exempt tens of sites by adding them to the exception/allowed list:

about:settings#privacy -> Cookies... -> Manage exceptions "You can specify which websites are always or never allowed to use cookies and site data."

i am constantly bothered by the Stack Exchange Network which constantly keep me logged-out and when i login, it redirect me to a homepage instead of a previous page, when i go back, it shows as logged out, so i have to F5 the page. And this constantly repeats.

Am I rendering my attempt to reduce tracking near pointless by allowing many sites like Microsoft's Github, Stack overflow etc. to permanently store the data incl. cookies?