yes. without background processing every web based service that has live updates would break. Email (Gmail/outlook.com/...) chat (slack/messenger/WhatsApp/Discord) SNS (fb/Twitter) even stack overflow and github have various forms of live update
Many services use an open tcp connection (e.g. websocket) rather than polling. Mobile platforms are doing the same thing, just on a system level. I guess service workers are the closest web analogue.