>>3279234>shouldn't we be idolizing lens designs for certain results
Yes. Within the same design, the performance is very very close. If you take all classic SLR 50 f/2 or f/1.8, they look incredibly similar regardless of manufacturer. Because they're all double gauss planars, or very slight variations.
Quality control and tolerances do play a role, but with any decent manufacturer that role is far lesser than optical design when it comes to performance.
To give you an example, even with notoriously "bad" soviet quality control, the vast majority of jupiters are indistinguishable from the Zeiss sonnars. And this is as extreme of a quality control as you can get. But since the optical designs are identical (not just similar), so is performance. Quality control has to be absolutely abysmal, or the defect rate absolutely sky high, for tolerances to degrade performance too much in the same optical formula.