Those modular monolith treatises, articles and videos presenting it as the less complex cousin of microservices with same benefits, I think it was all snake oil. They sold us dreams

Yes, it's more compact to house all components pertaining to an entity under one package. But it turns out all the hoops we jumped to hide them behind an interface, it's an overkill not necessarily the game Changer it was made out to be

I say this because one controller almost suffices for managing a resource. So does its associated service class. It can grow to 1k/1.5k lines at best. But never enough to be managed by multiple people and balloon into "a service". The idea was that these things are big enough to gain full attention. But the chances are slim

As long as you aren't dumping all your logic into your controllers, you're home and dry