Airbus has a novel approach to reusable spacecraft. Its still essentialy a design concept, a full size version hasn’t been built yet, and so is far behind Space X.
The nut of it seems to be preserve the expensive parts like the motor and avionics while throwing away the tanks. This lightens the amount to be returned, reduces fuel costs as a result. The returning section sits at the base of the booster, essentially returns as a glider and appears to use some form of propeller driven flight for the final leg to the landing strip. Space X by comparison tries to return the entire booster under rocket power to the launch pad. This requires substantially more fuel [ cost ] and also has yet to actually work.
In theory Space X is more reuseable because their whole booster lands not just the base of the booster. But from a cost and economic impact it may require more resources, time will tell.