After doing the basics (stone tools, safe base, light and food), I'd always do that as soon as possible. Diamond stuff is very useful for later parts of the gam

After doing the basics (stone tools, safe base, light and food), I'd always do that as soon as possible. Diamond stuff is very useful for later parts of the game, and you'll need a lot of redstone to build interesting circuits. It's its own form of exploration, at least in the versions with fun cave generation: you always end up in some cave complex that you can then explore. But I'm happy to see that it's less needed now, because interesting caves are more commonly accessible from aboveground.