Some of the shortcuts we use these days, like the HST instead of Y seams is due to our rotary cutting and machine stitching. If we did like our grandmas did and cut everything with templates and scissors, the more complex shapes would be the norm. As well, hand stitching Y seams, and the like is easier to do with hand stitching than it is with machine stitching. It's a tradeoff.
BTW, Y seams by machine are not that hard, just tedious. If you take the time, they come out great.