Well Sony's LCDs are from the last century and poorly implemented to non-existent touch screen (unless you buy the A1 for £6.5k which isn't available yet).
Most if not all other brands have better LCD implantation than Sony.
EVF really helps in maintaining better stability.... kinda handholding 101, you know press the camera against you face, hold your breath and squeeze the shutter almost like pulling a gun trigger.
Its not that one cannot get stable shots with LCDs just that using EVF or OVF for that matter is more stable especially when you are stretching the shutter speeds. Also better for tracking action, panning, day light shooting, better quality etc etc. And if you use heavy telephotos (100-400, 200-600 etc) handholding using the LCD is kinda not possible.