Where could I store my assets in an emergency if there are no more bitcoins?
None, because if there is no more Bitcoin, there will be also no altcoins, it means crypto era has been ended and died.
For these reasons, I strongly believe that Cardano will take over the DApp market instead of Ethereum.
I can't deny that Cardano is a very potential project with a great dApp. However, I don't think that Cardano is capable of taking over ethereum's position in this regard. Ethereum has been very solid and bear. whatever their pros and cons, they still have a positive side that is more convincing.
Would Cardano come close to Bitcoin in terms of decentralization? ( by using artificial intelligence and machine learning )
Would they have to switch to Proof of Activity for this?
This is too exaggerated, simply this is too exaggerated Cardano.