Looking across the NFL, the Ravens backs' yards per carry isn't too bad. It's not great either, because, as you say, the Ravens backs aren't special and no one would ever argue they were when our best back is a past-his-best Gus Edwards. (Although we'd have killed for even that over the last couple of years.) An affordable upgrade would have been nice.
What I'm saying is that it's good enough to get by, in the context of a Lamar Jackson offense. We're still a top 10 rushing offense in total yards and efficiency.