What the foundation has to do
The base needs to transfer the building load safely into the ground, keep the floor stable and level and help manage moisture and drainage around the structure. A perfect-looking room cannot compensate for a base that moves or holds water where it should not.
Where ground screws can work well
Ground screws can be useful where a low-disturbance installation, speed and reduced spoil are valuable. They can also suit some sites where getting concrete to the rear garden is awkward.
They still need suitable ground and an appropriate layout. The screw type, spacing and installation should be matched to the building and the site rather than treated as a universal shortcut.
Where concrete or other traditional bases make sense
Concrete solutions remain useful where ground conditions, loads or site geometry favour a more conventional base. They can require more excavation, spoil movement and curing time, but on the right plot those trade-offs are entirely reasonable.
The answer should follow the site survey
If a contractor specifies the same foundation for every property before seeing the ground, ask why. The sensible solution is the one that supports the particular room on the particular plot.