I would say the Stoke Space rocket is in some sense more novel than Starship, apart from its size. We have never seen anything like the Stoke upper stage before

I would say the Stoke Space rocket is in some sense more novel than Starship, apart from its size. We have never seen anything like the Stoke upper stage before. Which might be a financial problem, as developing such an ambitious design is likely expensive, and as a startup their funds are limited. A partly reusable design like Neutron (Rocket Lab) or Terran R (Relativity Space) is more conventional and probably cheaper to develop.