It's nice to have all of your db operations in Python and automatically integrated with existing Python tooling. It also makes it easier to refactor, organize, etc. SQLAlchemy comes OOTB with a lot of nice convenience tools and functions, and there's an ecosystem built around it, e.g. Alembic for schema migration. There are some cases like really complex queries where it can get in the way, but overall I find the tradeoffs are easily worth it for the convenience