Modular construction is a delivery method: build a box in a factory, truck it to site, stack the boxes. It is logistics dressed up as architecture.
Systematic construction is different. It is the discipline of designing the parts, the rules of their composition, and the supply line that produces them — as one continuous artefact.
A modular system gives you a faster box. A systematic one gives you a system: replicable, certifiable, improvable, and — eventually — boring in the best way. Boring is the goal. Boring means it works.