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/).
Also in the UK there’s https://utaw.tech/ and https://www.gameworkers.co.uk/
If there isn’t a union recognised in your workplace, you can build one yourself.
Usually (always?) regular working hours are compensated as usual. Then there’s rate for standby periods and another rate for each (half) hour when you get pinged and start doing actual work.
Also most tech companies don't have unions...