It's almost the end of the road for Steam on some Macs. After announcing plans to stop supporting Steam for Windows 7 and 8, Valve today announced it will drop support for Macs running macOS 10.11 El Capitan and 10.12 Sierra. The company made the announcement in a short blog post on its support site.
While the older versions of Windows will get dropped in Jan. 2024, the older macOS versions will get the boot earlier in Sept. 2023. Starting Sept. 1, 2023, the Steam Client will no longer run, and you'll have to update to macOS 10.13 High Sierra in order to play any games that run through Steam on your Mac.
Valve is dropping support for macOS El Capitan and Sierra for the same reasons it's dropping support for Windows 7 and 8: because "core features" of Steam use an embedded version of Chrome, which won't work on these older operating systems.
"In addition, future versions of Steam will require macOS feature and security updates only present in macOS 10.13 and above," the unsigned blog post reads.
This change will probably affect far fewer users than the Windows announcement, as Macs aren't nearly as popular for PC gaming. In the March 2023 Steam Hardware Survey, macOS and OS X consisted of just 1.41% of systems running Steam — and of the majority of those Macs were already running macOS 13.2.1 Ventura, which is the latest version. In fact, the oldest version even captured in the survey was macOS 10.15.7, an update to Catalina, and consisted of less than 1% (of the 1.41% of macOS/OS X users). So, yeah — these changes are likely to affect very few people.
Of the Macs in that survey, 54.88% were running systems with Apple Silicon, while the other 45.08% were still on Intel. El Capitan was released in 2015, with Sierra following in 2016. Security updates for those OS versions ended in 2018 and 2019, respectively.
With free updates each year, there's little reason for Mac owners to not upgrade, as long as their system is still supported. Apple stopped supporting 32-bit applications in 2017, with macOS 10.13 High Sierra, which led to tons of Steam games becoming incompatible with macOS.
That said, there's probably some people who will be affected by this announcement. But it looks like Valve is ready to modernize, even on this relatively minor platform.