It looks like the author is generalizing shortcoming in SQLAlchemy as faults with the concept of ORMs. ActiveRecord for example, treats SQL as “the source of truth”, per his definition.
Also, there is a whole section called "ORMs take over connection management and migration" and not a single point as to why connection management handled by the ORM is bad, only comments on migrations. Moreover, migrations are not an unsolved problem at all.
In Ruby, ActiveRecord solves all scenarios I have encountered gracefully, and trust me, I have dealt with tons of edge case projects.
Also, there is a whole section called "ORMs take over connection management and migration" and not a single point as to why connection management handled by the ORM is bad, only comments on migrations. Moreover, migrations are not an unsolved problem at all.
In Ruby, ActiveRecord solves all scenarios I have encountered gracefully, and trust me, I have dealt with tons of edge case projects.
For Python, I recommend Alembic: https://pypi.org/project/alembic/