To those having difficulty launching the arm64 version through Steam, this should be fixed now. Give Steam some time to update Factorio's launch options. If you're impatient like me, you can also force an update by opting out of the 1.1.71, build, or 1.1.x beta branch, letting Steam update Factorio...

Optimizations Added native support for M1 Macs. Thank you. Factorio now runs much faster. However, I seems like that the Steam beta version for 1.1.71 is not a universal binary and only runs in x86_64 mode, while the full download from the website is a universal binary and runs as arm64. Anyone els...