Marketing is much needed but I don't think it is a cub problem specifically but more an Egg/Goose problem looking at how all their clones have done.
Even if we exclude folks taking their money out of Cub, the ones in non-cub farms are selling all their cub to buy whatever asset their in and staking again. The cub farms sell half their cub to buy the liquidity pair.
Simplifying things but say someone makes 100 cub a day, they'll pay a 2 cub tax and sell 98 cub to buy say USDT-BUSD. I don't think there are enough buyers to absorb everyone 'selling their 98 cub'.