What particular algorithm the RTX 4*** series are good for? The RTX 30** are good for Ergo dual mining but I know that they aren't profitable anymore, now that Ethereum stops proof of work.
RYO and Conceal ( cryptonightGPU ) ? Or KHeavyHash
Every single coin is mining at a loss with the price of cryptocurrencies nowadays and the price of electricity in most of Europe skyrocket high,does not make sense to mine so the only possibility to start doing it is if you believe in a coin that you think will explode in the next bull run which everyone is predicting to be in the year 2025.
It does not matter now whichever coin you mine,just mine what coin you think has a great developers team behind,a great roadmap and hope for the best,if you can't afford to mine for the long term then don't mine at all.