Most other rockets of that size succeed with minor issues in first launh. Launching the rocket shouldn't be that much different from other rockets. Re-using it is a totally other ball-game, but why not do it, how they did successfully with Falcon 9: Get it usable and then figure out re-usable. I.e. get Starship to orbit without reuse (but reuse ready), launch Starlink satellites, then reuse boosters, then start to recover and reuse the ship. Even though the development itself is iterative, it is not "agile", where you start by a minimal viable product, and then at features. This is going for all the features, before they have a product.
They also seem to be caught by quality problems. And maybe they try to make it too cheap by relaxing quality too much, for instance building it outside and no clean room.