Sad to see OSH go. They never quite lost the old-hardware-store feel and staff. Sears' ownership seemed to be relatively benign, and adding Craftsman to the brand collection was a fairly good thing. The real end was the Lowes' takeover, not so much Amazon which is still kind of clunky when it comes to building hardware. It was obvious that if Lowes didn't use an OSH site for one of its own stores, the OSH would eventually close. It was really obvious where I live - OSH was across the street from a Lowes, and rapidly went downhill closing about 5 years ago (it's now a Sprouts grocery store).

As for ACE - all of them in town closed years ago, and the nearest is about 6 miles away in the next town. They tend(ed) to be small, independent stores, at least in this area, with an ACE affiliation. Never were well stocked or convenient to use.

So now we have the remaining hardware overlords: Home Depot and Lowes. Their pricing and availability sometimes differ in surprising ways, so it's often worth comparison shopping, but on the whole we have now reached the conclusion of the Rule of 2 1/2: 2 competitors that are about the same size and act as a duopoly (minimal competition). All the others added together come up to about 1/2 of one of the big ones, working in bits of the market that the big boys don't care about.