Always have been.
GM, and Rolls Royce used "select" fit for more than half a century.
Acknowledging that there are tolerances in manufacturing, manufacturers used to pick/make not quite to spec equipment, and assemble it to get the clearances that they were after.
There were bearings over and under dimension, 1/4 thou, 1/2 thou, 0.75, 1, 1.5 and 2, so the machining of the crank and bores could me matched exactly to the right bearing or piston to get exactly the clearance that was specified...and engine could have 8 different over/undersizes, and be "perfect".
Makes remanufacturing an engine difficult, when you have to "fit" parts together to get the best, or the best compromise.
The old ways delivered precision fit, at loose tolerances.
Japanese expect that parts are manufactured such that every piston can go into every block, way more expensive set-up,and it works most of the time in modern times.
I'd be surprised if clearances were that much better controlled than in the past...the SBC in my brother's 1969 Holden Premier still called for 5W-20, even 'thought there was no such available in Oz at the time.