Oh, it's you again... however...

The Workshop is a lot of work, building an airship and submarine fleet and level them up and unlocking all the blueprints for crafting is something wich can take months and costs a lot of money (or a loooot of time when you gather everything yourself). The millions of gil are not coming out of nowhere, even when your fleet is built and ready you have to rely on RNG for valuable items and / or invest into building stuff like housing skins to sell.