As far as I understand Starship can only reach LEO and requires refueling from several refueling missions while in orbit for longer missions. Great if spacex is able to pull it off, but it is years if not decades until they get there.
Predicting decades when it took them only 3 years to go from "nothing" to on the pad is a bit much.
This isn't kerbal space program... Fluid's gonna fluid dynamics in a 0g environment...
I bet it won't take more than 5 tries to do a full tank Starship transfer. And SpaceX iterates quickly
Every single person I've heard say this hasn't given a reasonable reason why it's difficult other than "we've never done it before". Also on-orbit refueling has been done, just not with cryogenics. Additionally it's only been done in zero-G with bladders. A slight vehicle spin to settle tanks seems like it would be sufficient to feed some low speed pumps without bladders.