They need to remove a lot more things from vendors, or limit the amount you can purchase from the vendors each day. That will increase the player economy.
They already removed many (not all) of the second level tools.
I think produce should be limited, so people have more incentive to grow/sell to users rather than just themselves. Seeds should be limited. Everything available at the vendors makes the auction and trading not as worth while.
Adding a vendor for housing upgrades that take currents would put a big money sink and solve the issue of people just hording currents and the inflation.
And while I don't really like the idea myself, I think there should be a limit to the amount of times a tool can be repaired. Or each time it's repaired to full from broken, it loses 1 max durability. Something to create a need for tools beyond the initial purchase.
Blockbuilding could be expanded for use in housing upgrades, decorations, etc.
I don't mind everyone learning everything, because at some point it becomes inefficient to try and do it all yourself even if you can.
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Can't sleep, clown will eat me.