Nowadays most people use electronic money instead of banknotes, so the process of eliminating cash has already started. Developing and launching CBDCs will take up to 5 years. It will take above 10 years to become finally cashless.
Indeed, we already use digital money anyway. But in order to fully pass, I think it takes one generation.
Are you really sure that in 10 years we will become cashless? In certain countries, maybe - yes but not everywhere. Cash is still preferred money for some people because they have full control on it. You can't control your banking account because they can lock it anytime they wish if there is something wrong. In overall, not your keys - not your coins applies to those who own bank account and cards, not your cash - not your money. Crypto is a great deal in digital world when it comes to money but I think that both, cash and crypto has so unique pros and cons that it's hard to say (for me) the actual winner here for our welfare.