I believe that sometime in the future, perhaps within the next 5-10 years, Bitcoin's role will begin to shift from being merely a speculative instrument to becoming a decentralized financial infrastructure.
Do we have to wait for decade when this is happening already, from what we know bitcoin to be, as a decentralized digital currency, but let's not get it wrong because Defi may not directly work perfectly to how the structure of bitcoin network has been built on, so it's more better that we stick to the network protocols and apply it's uses to our various demands for the same digital currency because bitcoin exists today and will always remain the most useful digital currency under a decentralized network.