> Previously, the time-optimal strategy to acquire iron and diamonds was to dig a hole deep into the earth and then bore straight paths. This was exceptionally grindy (fans would say zen, detractors would say tedious), but effective.
I'm not a big Minecraft player, but I'm pretty sure the time-optimal strategy for getting diamonds consistently was to set up a deliberate mine topology which is mathematically efficient, not just dig forward in straight lines. AFAIK diamond mining was the only thing that couldn't be automated; for iron the time-optimal way is to construct an iron farm, i.e. engineering, not grinding.