A lot will depend on rural areas too.... Dems will not win in many of these areas but trimming margins in these places matters a lot. Obviously he still lost by a lot, but Biden did manage to win back vote share in a lot of areas of the Upper Midwest, which made a difference, particularly in WI and PA.
In general, I do think the Dem Party has come a long way in understanding that turning 75-25 counties into 70-30 or 65-35 can go a long way.... the votes all count the same regardless of where they are cast.
With respect to Ohio, if they were to have any chance there, it would have to involve more of this.... Ohio is just tougher than much of the Midwest (particularly MI and WI) because so much of the southern part of the state is Appalachia adjacent, and much more hostile to Dems than even conservative parts of MI or WI are.