Thread:707Mithrandir/@comment-28905095-20170319213052/@comment-26335978-20170319220913

"Infinite" worlds are not actually infinite but so large that it would be impossible to explore the whole thing in a lifetime.

I would recommend thinking about them in terms of old worlds (excluding, of course the occasional missing block/items/mobs), can it be infinitely obtained if you cannot explore anymore?

Yes, Iron would be non-renewable if it was not dropped by mob.

Mobs spawn infinitely while worlds technically cannot be infinitely explored.

I hope this helps!