Cracks are a fact of concrete unless your sections (cold joints) are tiny. Engineering ensures they don't matter because they are in controlled places.
Right. Anyone with a block house or foundation has cold joints everywhere, sometimes tied together with rebar, but sometimes not. IRC allows straight up plain masonry (no rebar) for houses in most regions of the US, which gives you hundreds of cold joints in running bond.
IRC will even allow you to use masonry as a footing, although you rarely see it.
