Yes. The developers of Bitcoin Knots created a copy of Bitcoin Core project which in software development is called a
fork (not to be confused with what we call
fork in cryptocurrencies). They made certain non-consensus related changes which they believe is an improvement on the original project.
Bitcoin Core wallet software forks can be used and are alive well with time while Bitcoin forks are altcoins and also known as shitcoins or dead coins.
How Many Bitcoin Forks Are There? You will be surprised!!!BTW if you ask me most of the stuff you read these days about "core vs knots" is being blown out of proportion.
I think the answer is quite easy to get and Bitcoin Core is more widely used by Bitcoin users.
The Bitcoin Nodes Summary with statistics to prove how Bitcoin Core outperforms Bitcoin Knots wallet softwares by Bitcoin Node Operators.
https://coin.dance/nodes