The ability of websites to send push notifications has extremely limited practical utility. I’m fine with getting notification from the website that lets me send and receive text messages from my browser, but I have no interest in receiving breaking celebrity news notifications, and find the prompt as to whether I want to receive these very annoying.

Fortunately Firefox provides a way to turn these prompts off: in Preferences, search for Notifications, and check the “Block new requests asking to allow notifications” checkbox: