Why does Comcast let known phishing emails flood our accounts? I get several every day. They are the ones on the danger lists. It should be easy to filter these out of all accounts.
Unfortunately it is not easy. The scammers put a lot of effort into bypassing filters and algorithms.
Email providers are always one step behind unfortunately as there isn't really any way to proactively know what tactic they will use next.
If the filters are too agressive, legitimate mail goes to spam (or gets blocked completely) and people will complain about that. It is a fine line.