A spreadsheet. A chat app. A document editor. A map editor. Anything where information is on screen & needs to be live. Aka, what a huge part of the web today does.

Except all that information is on screen, shared live, via the web. A chat app talking to the next tab in the window isn’t worth much.

So what you do when your users have 20+ tabs open to the same service? Have each tab keep just itself up to date?

Is 20+ tabs of the same service, each needing the exact same data, a common scenario?

The "exact same data" is often some change. Like user statuses in Slack. It's not terribly uncommon.

Opening a bunch of tabs is up to the user. I develop web apps for business users and often they open many tabs. But even me on reddit or hn I'll open a bunch of tabs to basically queue up reading.

It depends. Sometimes, yes, users do have many different conversations going & tabs for different conversations.

Or they might be flipping between different sheets in the spreadsheet. And perhaps those sheets have cross relationships. Or perhaps the user changes which sheet they're looking at & has old data.

Whether or not it's common doesn't change that it's a concern that good developers strive to develop for, and it's something that ought be expected. Tabs are part of the web, are something that support user-agency, and it ought to be common that they are well supported. Now, we can start doing the job we ought to do.