I don't know why people project Zoro's Dream on the other Strawhats
Chopper doesn't wanna be the best Doctor, Nami doesn't wanna be the best navigator, Sanji may never surpass Zeff as a cook, Franky might still be behind his Big Brother as a Ship maker, Brook doesn't wanna be the best musician.
Because they have in their mind "every strawhats wants to be best in their field" and then argue from there, despite often times there is no tangible way to assess that in the first place.
Strawhats are special in their field from the get-go, and nothing says they will somehow become the best.
If Law could actually cure all diseases, they might have a point though, but so far nothing suggests Law is special beyond surgery at which he is the best but even then, the other Strawhats dream of accomplishing something someone already has done.
Franky´s literal dream is to do something his teacher already did, make a ship that can travel or has traveled even to the most dangerous and remote places.
Luffy´s dream is something Roger has already accomplished, Robin won´t be the first to learn about the history after 800 years and so forth, so neither first nor best. As far as we know, the Oro Jackson navigator has a map of the entire world, Brook´s dream is very personal but nothing grand...
Edit: With that train of thought, Sanji´s dream might actually be the only one nobody else has achieved in the last 8 centuries if the All Blue is really born out of the destruction of the Red Line.