I think this way is correct because means manual app installation according to the system requirements I use. The rights change is maybe not best idea.
Anyway, interesting your opinion or how do you work with systemd+rust apps
If you want to use your locally-instapped app as systemd service (including ones made with cargo install), you likely want to reach for user services, not system-wide ones. If you want to use system-wide service, well, you have to somehow install the app system-wide, be it manual cping or using system package manager.