I was not aware of this until today. People use work profiles on Android to isolate their more privacy invasive apps. If you want those apps to be tunnelled through a VPN, you would have to install the VPN application you use on your work profile separately and turn it on separately in your work profile.
Actuallyz the intended use of work profile is for… Work. You don’t want the corporate VPN to be Tue phone-wid3 VPN - do you?
The design is logical. Since we are all misusing it, I think it would be useful to be able to toggle a “share VPN” switch.