It's also a lot easier to mess up evolving the logical schema and result with unexpected and incoherent database state if your store doesn't enforce the logical. schema. Sure, the more the logical schema is enforced, the more you are forced to do up-front when the logical schema changes, but that work prevents you from:

(1) apply a data migration that fails to result in a state that complies with the logical schema, or

(2) producing a state inconsistent with the logical schema because your application code doesn't correctly observe the schema, as defective code will fail for violating constraints instead.