This is counter to my experience, I've worked with multiple small teams (6 people at most), that all have datastore integrations, and CI/CD pipelines generally make them faster.

> those sort of complex deploys block other people's work

I think this is the root cause of your concerns, the database migrations seem to always be backwards incompatible and therefore deployments and migrations need to be synced, blocking other changes.

Typically CI/CD pipelines are never blocked.

Making sure the database migration / code change is backwards compatible is minimally more tedious (i.e. multiple incremental changes across multiple days), but overall speeds up development.