Lc0 is a good alternative. While it is not as strong as Stockfish in terms of playing strength and tactical problem-solving, it can offer interesting opening ideas, particularly in the context of human games. For example, a grandmaster preparing a specific line to counter an opponent before a game.

It's a bit tricky to install, as you have to choose depending on your hardware: CUDA for the newest NVidia graphic cards, CUDNN for older NVidia cards, ONNX-DML for other graphic cards, DNNL-BLAS for modern CPUs and OPENBLAS for older CPUs.

These binaries are only for Windows and Android. If you have Linux, you will have to pass through the pain of compiling this engine by yourself.