The answer to that question could probably fill another blog post :D

Long story short, Rails and dependency inversion equals lots of friction. The whole framework is built on the assumption that it's OK to access everything from everywhere, and over the years we've built lots of tooling on top of those assumptions.

E.g. we heavily use https://github.com/Shopify/identity_cache with active record associations that cross component boundaries.

We also have a GraphQL implementation that is pretty closely coupled to the active record layer and _really_ wants to reach into all the components directly.

All of those problems can be overcome, but this is definitely an area where we have to working against "established" Rails culture, and our own assumptions from the past.