Comment by Dragory

In my experience, 99% of the relationships I fetch fit the basic one-to-one, one-to-many, many-to-many definitions that pretty much all ORMs support. For these cases, the queries are generally more than efficient enough and there's little reason to reinvent the wheel and implement the code for fetching those relationships yourself.

For anything more complex, I agree. But for the common case of fetching simple and often (depending on your project) nested relations, I definitely enjoy the abstraction provided by ORMs.