For Chrome, they are developing an automatic spam-blocking mode in notifications
A mode for automatic spam blocking in push notifications has been proposed for inclusion in the Chromium codebase. It has been noted that spam through push notifications is among the most common complaints sent to Google support. The proposed protection mechanism will address the spam issue in notifications and will be applied at the user's discretion. To manage the activation of the new mode, the parameter "chrome://flags#disruptive-notification-permission-revocation" has been implemented, which allows users to control this feature.
