Many ways for SE to fix the inventory system have been proposed in this thread and many others in the past. Are you ignoring them on purpose for the sake of argument?

They could start by adding a currency tab instead of giving us new primal tokens - or Beast tokens - every patch. FFXI has been using one for years.

A glamour book would free up space for materials.

Getting rid of some the Grade X prisms that are basically just clutter would help too.