First of all, Bitcoin was never meant for instant payments. The average time interval between the blocks is 10 minutes, so instant payments are not possible (unless the vendor doesn't ask for confirmations) even if the Mempool is largely empty. It is useful for large payments, which doesn't need immediate confirmation. An international wire transfer takes many days (or even weeks) to get confirmed, so compared to that Bitcoin transactions are relatively faster and cheaper. And now the Mempool size has started to decrease once again, and the median transaction fee is around $4.50.