That's very easy to explain. Falcon was a rocket designed by real rocket scientists and experts in their field. Back then Elon actually listened to them. But for Starship he began to believe that he was competent enough in rocket science to make those calls and ignored anyone telling him otherwise. That's why it's such a mess, had multiple redesigns and can't really get anywhere. Starship will not deliver what was promised, because the design is inherently shit. First it was supposed to be carbon fiber (nod to OceanGate) but that turned out to be shit, now it's stainless steel that after a round trip belongs on a scrapyard not on a rocket. Not to mention having to use tiles that was a huge problem and cost related to Space Shuttle. Now Starship has the same problems and loses tons of them when going back. How is that going to help rapid redeployment if you need to check 1mln tiles and replace every single one that's missing or defective (along with it's mounting, I don't even want to know what happens if the fastener breaks and do they plan to fix that).
You can see the same thing with Tesla. Until Elon listened, they made good cars. Once his ego pumped and he decided he knows best, he pulled the plug on radar/lidar and that basically stalled self driving for a decade, same with 4680 battery, gigantic aluminum stamping pressess etc.