Maps VTT suggestion
One feature that VTTs should theoretically be able to offer that makes them superior to a physical table would be smooth way to handle the problem of "Oh crap the fight is heading off the edge of the map." We (as DM) should be able to click on the edge and click some buttons to add extra rows or columns. They wouldn't have any map or art on them (maybe just give the DM an option to pick a background color from some basic presets), but it would still be a massive improvement.