The 23x more launches figure comes from HLS (Nasa sponsored mission to the moon). They may well change the configuration of that anyway, but if you want to refuel in orbit, that's what it costs. It's hard to get fuel to orbit (or any sort of payload). Previous Moon missions haven't refueled anything, but they couldn't return anything heavy from the moon's surface, the vehicle got smaller and smaller as it went and many parts were left behind, so it's not comparable. You can be sure if it's cheaper to somehow do this mission with expendable boosters, they'll think about doing that.
On a normal mission just to earth orbit, there is one booster and one starship, and reusing the booster is more a question of why not save some money for a little more propellant use? The reususable booster doesn't contribute much extra weight, it uses little propellant for boostback and landing.
The booster also doesn't go all the way and you need a booster if you're going to reach orbit (due to that equation), so it doesn't take much to make it reusable. So all in all, why not make it reusable if you can? What would you save from using expendable ones?
The 23x more launches figure comes from HLS (Nasa sponsored mission to the moon). They may well change the configuration of that anyway, but if you want to refuel in orbit, that's what it costs. It's hard to get fuel to orbit (or any sort of payload). Previous Moon missions haven't refueled anything, but they couldn't return anything heavy from the moon's surface, the vehicle got smaller and smaller as it went and many parts were left behind, so it's not comparable. You can be sure if it's cheaper to somehow do this mission with expendable boosters, they'll think about doing that.
On a normal mission just to earth orbit, there is one booster and one starship, and reusing the booster is more a question of why not save some money for a little more propellant use? The reususable booster doesn't contribute much extra weight, it uses little propellant for boostback and landing.
The booster also doesn't go all the way and you need a booster if you're going to reach orbit (due to that equation), so it doesn't take much to make it reusable. So all in all, why not make it reusable if you can? What would you save from using expendable ones?