There are some crypto currencies that have adopted the fixed supply of Bitcoin, and yet they were not able to replicate what Bitcoin has done. However, in this market, if you try to observed, if you are not the prime mover then I think you will not be successful. You really need to be unique in order to gain the consensus of the market. And most altcoins try that, to go against the principle of becoming SoV, and yet they still failed. Plus, we've heard scarcity and limited supply, but it's hard to implement.

And without Bitcoin’s trustless decentralization and immutability, that supposedly copy cat is not that strong. And even fork of Bitcoin, the almost exact copy of itself, failed miserably. That's why Bitcoin is truly unique in itself, even if you copy it in code level, no one can duplicate it's success.