I’ve recently discovered an extension called Consent-O-Matic, which automatically completes cookie forms. Also, uBlock Origin includes lists (disabled by default) that will block all sorts of annoyances, including newsletter shite.
The best way to avoid scam emails is just to change your email account’s password to a random string, not save it, then log out. I’ve also shredded my SIM card so I can’t receive scam texts.