There's other examples of this kind of approach, too, writing straight C Common Gateway Interface web applications in public-facing production use - What comes to mind is the version control system web frontend that the people who write wireguard use, cgit [2] - If it's really so crazy then how come the openbsd and wireguard people - presumably better hackers than you - are just out there doing it?
Other places you see C web application interfaces include in embedded devices (SCADA, etc) and even the web interfaces for routers, which unfortunately ARE crazy because check out all the security problems! Good thing people at our favorite good old research operating system have done the whole pledge(2)[3] syscall to try and mitigate things when those applications go awry - understanding this part of the whole stack is probably key to seeing how any of it makes any sense at all in 2022. It sure would be nicer if those programs just crashed instead of opening up wider holes. Maybe we can hope these mitigations and a higher code quality for limited-resource device constraints all become more widespread.
[1] http://undeadly.org/src/ [2] https://git.zx2c4.com/cgit/ [3] https://learnbchs.org/pledge.html