If you are going to use a centralize database coupled with edge compute, you may end up with far worse end-to-end latencies if your compute<->db does multiple roundtrips per request (which is fairly common in practice). In most cases, you need compute and db to be colocated.
I am skeptical of edge compute being generalizable. I do forsee a bright future for it for embarrassingly parallel problem space, where data sharding can be done cleanly based on an end user.