What's the benefit of just using plain owasp modsecurity?

It also exists as a docker container as an nginx reverse proxy with modsecurity extension.

https://coreruleset.org/docs/6-development/6-6-useful_tools/...

ModSecurity doesn't offer antibot, bad behavior, certificate management, ... You can find the full list of features here : https://docs.bunkerweb.io/latest/features/