Conceptually, yes they are the same unit. Which is part of the beauty of it; it's not a radical paradigm shift like monolith->microservices or systemd->k8s. But the developer experience/productivity of bending Django or Rails in different ways is far superior to bending e.g. MySQL or PostgreSQL*. HTTPS is plainly a much better, and more widely available, integration protocol than N different SQL dialects.
*much respect to what the Crunchy Data folks have accomplished
There are pros and cons to the abstraction that an ORM brings. Assuming it’s decent (like Django), you can be guaranteed that the queries it generates are good enough. They’re not always perfect, and sometimes need help depending on how convoluted your schema and desired query are, but they’re decent.
The downside is this can cause devs to never have to think in terms of what the DB is capable of, so they may not consider writing the code such that the ORM decides to write the query differently. I’ve specifically seen a dearth of semijoins in output, even though they’re a common construct in RDBMS, and often far faster for the desired end goal. Sometimes the SQL planner itself will produce them, of course, but that’s not a guarantee either.
*much respect to what the Crunchy Data folks have accomplished