Monolith apps can have many dependency checks and it is not really an issue but I get your point. It can become messy. What I have seen gone into sidecars is TL

Monolith apps can have many dependency checks and it is not really an issue but I get your point. It can become messy. What I have seen gone into sidecars is TLS-termination, caching, authentication, service clients, metrics and logging. Things I would prefer to have in a dedicated proxy layer or in the images.