SQL alchemy is good for fairly straightforward queries where you mainly need to do "select * from ..." and you want to pull down related rows from another table based on a foreign key in the first table as a separate query. It's also good if you have a lot of junior devs that don't know SQL and you want to encapsulate complex sql logic for them.
If you're doing anything more complex than these basic sorts of queries and subqueries, or your developers are proficient in sql, using even a very good ORM like sqlalchemy is going to be a step down.
Since you say you're doing this all yourself, and SQL is probably the most ubiquitous programming language (in terms of percentage of jobs requiring it, not total LOC) so learning opportunities there are more valuable, I would go direct.
If you're doing anything more complex than these basic sorts of queries and subqueries, or your developers are proficient in sql, using even a very good ORM like sqlalchemy is going to be a step down.
Since you say you're doing this all yourself, and SQL is probably the most ubiquitous programming language (in terms of percentage of jobs requiring it, not total LOC) so learning opportunities there are more valuable, I would go direct.