Yes, you can mine Ethereum with a gaming PC. In fact, a lot of people use their gaming PCs to mine Ethereum.
The main reason why people use their gaming PCs to mine Ethereum is because it is very profitable. For example, if you have a gaming PC that is equipped with a high-end GPU, you can easily make over $100 per day by mining Ethereum.
The only downside of mining Ethereum with a gaming PC is that it can be quite expensive. In order to mine Ethereum effectively, you will need to invest in a good quality GPU.
Additionally, you will also need to pay for electricity. Overall, mining Ethereum with a gaming PC is still quite profitable, but it is not as profitable as it used to be.