The M-series is very directly comparable to, say, an AMD Zen 3 v-cache or a Zen 4 processor. In many scenarios the AMD is faster, and in others the M-series is faster.

The main advantage of the M-series if for laptops on battery. Desktops, gaming, and software development is still significantly better on Intel-compatible desktops. E.g.: I can run Windows 11 with WSL 2 and Docker. That lets me develop using multiple huge ecosystems of tools seamlessly. With Apple, you get immediately relegated to a tiny corner of "optimised for M1" software, and have to either emulate or use cloud-hosting for everything else.