Commonly Horizontal or Vertical DAT Racking is Installed in Residential Rural locations or commercial Solar Farms.
Largely to do with digging a 60cm deep Trench for Electrical conduit & having clearance from Shading for buildings & terrain etc.
There are bespoke Rooftop DAT Racking, but as Marty said, the Affordability of changing the Racking type in the Short term is Not really worth it.
However, as DAT provides superior energy Generation from 10~12 hours per Day depending on your latitude location, the generation over the 25year life of the system Panels, would be approx. double the Energy Generated.
As say, if you have a common system of 22x 300W Panels (6.6kW) System it will Generate 12’000kWh/p Year, compared to DAT that will Generate 25’000kWh/p per Year.
So, have fun analyse that !