Bitcoin can be cloned and Bitcoin can be forked, and at the end of the day, these two are not Bitcoin but rather an altcoins.
Bitcoin cloning or forking results that exist to date even provide statements that they are the best compared to the original Bitcoin and have many advantages.
and see how when BCH, BSV, the results of the Bitcoin Fork stated that they were The Bitcoin Original Blockchain and superior to Bitcoin.
Is it a statement that is just a hoax and eventually unpopular again and abandoned.
They are just a bunch of Altcoins that ride on the fame of Bitcoin.
A-Map-of-Bitcoin-Forks_V2Cloning Bitcoin is possible because anyone can copy the bitcoin codebase and create their own coins but as I stated they are not Bitcoin since they run in different blockchain or network. This article:
https://casebitcoin.com/critiques/bitcoin-can-be-cloned gives an explanation of the question @OP
Bitcoin remains Bitcoin no one can clone.
The network remains the Bitcoin network, if you want to consider the original Bitcoin clone look at the Lightning Network,
it is a clone of the Bitcoin network which is faster but still in the development stage.