Denom is the first initiative ever to build an on-chain democracy. This is no small feat, and to make sure everything works as intended and no exploits are possible, rigorous testing will have to be done.
In addition, a lot of the technology needed to make this work is still in early development, with many teams and protocols racing to get there first and no real large-scale testing done yet.
That is why, rather than launching these systems in one go, Denom governance modules will be rolled out in phases, each building on the next. This ensures every sub-module can be thoroughly tested both technically and socially, before adding additional layers and increasing complexity.