Rewriting everything is fine, as long as it's not in C or similar insecure by design programming language, it doesn't invent DSLs on top of INI/YAML/JSON files,

Rewriting everything is fine, as long as it's not in C or similar insecure by design programming language, it doesn't invent DSLs on top of INI/YAML/JSON files, uses proper architecture with clearly defined boundaries and protocols, allowing custom application-specific management instead of forcing everyone into author's narrow worldview full of incorrect assumptions. So as long as you are not doing what systemd does. Centralized management/monitoring in general sucks. People don't seem to understand the problem and keep reinventing new centralized architectures suitable for their own special cases, instead of addressing that on architecture level.