Glib answer: centralize! Honestly this seems to be a cycle.
New management comes in, everything is centralized, big, slow, etc. The eggs-in-one-basket state.
They need to do something to make a mark so why not decentralize! Big project, political spin on whatever outcome, probably an imperfect one with some issues: complexity, silos, cost.
Next new management comes in - what can we do? Economies of scale, simplicity: let's centralize, woo!
And the corollary: new development team comes in and says everything is crap (while breaking it) and tells management they need to make a new system from scratch.
Cash strapped business goes ahead, because developers are always right, and the old team never resolved new requests anyways. Management puts the cost press on the team, so they end up making a shiny pile o’poo that does what the current needs are, but at a much higher cost than stable maintenance.
New management comes in, everything is centralized, big, slow, etc. The eggs-in-one-basket state.
They need to do something to make a mark so why not decentralize! Big project, political spin on whatever outcome, probably an imperfect one with some issues: complexity, silos, cost.
Next new management comes in - what can we do? Economies of scale, simplicity: let's centralize, woo!
And repeat ad infinitem...