GPU chips are needed not only for gaming, but also deep learning and big data science applications.

GPUs for mining are also another realistic application and although the mining rewards might be getting smaller for Bitcoin, there are a whole lot of other cryptocurrencies which could use GPU to mine. It's up to you if you want to establish yourself as a player in the mining game, but it is getting more expensive to make a profit with Bitcoin.

I would recommend just getting a dedicated ASIC miner from Bitmain if you want to try out mining at home.