hhgregg (HGG) and Conn's (CONN) are some of the rare survivors in this field, and it's because they key in on heavy appliances, furniture, bedding, and even lawn care equipment that's harder to secure cheaper online, given the bulk of the items.
Best Buy naturally sells appliances, but that's just 5% of its business. If Best Buy wants to emphasize big-ticket items that are purchased very infrequently -- thereby taking on the smaller hhgregg and Conn's -- it would probably have to close all but a store or two in each of its major markets. There just isn't enough business for these products to justify Best Buy's existing store base and square footage.
In short, it's not going to happen.
Best Buy may be in the process of closing nearly 50 stores over the next few weeks, but there will be more of that in the future unless trends reverse and positive catalysts emerge.