Starship is in testing. Where other space companies spend years to decades testing their designs in simulations, wind- and plasma tunnels with gigantic costs (Blue Origin is developing New Glenn since at least 2013), SpaceX is building test articles and just fly them. Those test articles are not the final version of the rocket and they are not meant to complete an entire flight flawlessly. They are akin to alpha builds in software development, designed to test features, not to be a finished product.