RVDT:
Part of the problem is that a basic certification for Part 27 does not require an attitude indicator - the requirement for an attitude indicator is often (depends on country) in the operational rules - and only then for commercial operations.
Ditto for things like gyro compass. Look at the baseline 'top drawing' of most light helicopters cockpits to see what is the minimum. Some light single engine machines, particularly of European extraction had to have a complete refit of night lighting to operate in North America as the country of origin did not allow single engine aircraft to fly at night - because in that country night flying is IFR, and the original night lighting was just the wander light...
Look deeply for a definition of VFR - at the most fundamental level it will say something like '…ability to orient the aircraft position (in this case meaning not just geographical position, but height above ground and pitch and roll attitude) by use of visual references from the ground or water.
There are lots of times when this isn't possible in daylight (3 miles vis in a milk-bowl day with no discernable horizon over a lake that's 5 miles wide, or on a overcast day with 1 mile vis over a snow-covered lake are just two examples) and people have paid with their lives to learn, too late, that it wasn't VFR.