[ExoticPearTree]

> ... all you're left with is your speed, altitude and attitude.

Which is all you need. You have the same information in any other aircraft, most only have airspeed and altimeter info. An attitude indicator is of great help when you're flying through clouds so you can check that you're actually flying in level flight - it is pretty weird to find out you're actually flying banked but because you have coordinated flight you don't feel it.

[arghwhat]

Have you flown a modern fighter jet while suddenly your helmet integrated flight displays and navigation went out and you had to reorient yourself and rely entirely on nothing but your knee-mounted false horizon mid-maneuver, while attempting instrument landing under - and I quote - “extremely challenging cognitive and flight conditions” where you due to repeated electrical glitches have lost faith in the aircraft and in particular its ability to transition back from SVTOL to regular flight operation? Because that was the situation that you claim was fine.

You can keep an otherwise fully functional aircraft in stable level flight using a horizon, but that’s neither interesting nor relevant. This was not a lightweight aircraft cruising above the clouds with nothing around it.