I don't believe it's physically possible for anyone to be available at 10 minutes notice for 168 hours straight. And if it's possible, it would be deeply unhealthy. But if they did achieve this, then yes they should be paid some very large amount of money. But that doesn't just happen -- pay isn't fair, it's about power. So a union can help to negotiate this, or ideally, better working conditions.

> Also most tech companies don't have unions...

In Europe, there are plenty of unions that cover tech people. I'm a member of Prospect (https://prospect.org.uk/).