It's not that simple to run your own relay. You would also need to buy/rent a server which is expensive. It's not for everyone.
Discussion
I run one on my computer at home
nostr-relay-tray can easily enable you to run your own relay on your home computer.
how are you hole punching?
I've written a simple reverse proxy service and integrated it into the nostr-relay-tray. It can be easily enabled.
https://github.com/CodyTseng/pigeon
Not everyone has a home computer in a country that allows unrestricted internet access
Not everyone even has a home computer at all
Citrine runs on your phone.
If every user should use it then put it in every nostr app instead of expecting people to install it