I wish cities would treat high streets as public commons, rather than particularly valuable private real estate. Landlords are just looking to make the most rent possible and don't particularly care whether their tenants have positive utility for the community or not. Similarly, landlords have no problem keeping store fronts empty because they are holding out for a high paying tenant and have certain tax advantages.

I live in a little community outside Boulder, and we have a nice little main street area, only a few blocks, which is a good size for our community. There's a few restaurants, a cafe, a community space, some boutiques, all of which encourage foot traffic and liveliness. But recently, a little book shop devoted to kids books was forced out due to increased rent demands, and an architecture firm moved in. What was previously drawing maybe 100+ people a day to the main street now attracts 5 employees who work in a closed office. Not the end of the world for the main street, but if a few more shops make a similar decision it will be completely dead.