Execution API vs Ethereum JSON-RCP API

It's been some time since I don't use JSON-RPC in Ethereum and just found this Execution API (and the Beacon API).

I tried the new methods present in this API (i.e., debug_* and engine_* ) against a geth and Infura and they are not recognized. However, they recognize the classical ones I was used to (i.e., web3_* , net_* , ...). Also, I found out these methods are still referenced at [Ethereum](https://ethereum.org/en/developers/docs/apis/json-rpc/)

So, can anyone explain me what is the purpose of this Execution API? Will it replace the existing API in the future?

Thanks