This is not strictly true, BTW. Most OSes don’t peg their browser to the OS 1:1, but Firefox and Chrome in particular limit what versions can be installed on old Windows and Mac computers.
Firefox ESR won’t go beyond 115 for those machines. Chrome stops at 109. Both are getting the banner.
It isn’t just old iPhones but older desktops and laptops too, many of which are perfectly usable (if vulnerable, yes) and otherwise work fine with the boring parts of the web that boring old people still use. It’s some of those same people who are still using forums instead of, say, Discord or whatever the kids are on today. And it’s them who are getting hurt by this change that prioritizes developer experience over user needs.
Discourse, and most of the web, has been working fine without needing relative colors, lookbehinds, or sub-grids. Somehow we got by. There was always a need for new features, but that was responsibly balanced by graceful degradation, excluding users only when no alternative was possible – which shouldn’t be very often when a software’s fundamental job is to show text posts with a few images.
I know many of us techies like to stay near the front of the curve, and we’re used to chasing that ruthless bleeding edge, but it cuts both ways. In this case it’s hurting real users who rely on Discourse not just for a profitable modern experience, but for being able to stay connected to their long-time communities.
It’d be one thing if this were a critical security issue that could not otherwise be fixed. But it sounds like just a minor improvement in devex (please correct me if I’m wrong) that’s more about making future development easier and faster. In that case, does it have to be so urgent? Two weeks notice? Surely it wouldn’t do much damage to wait a few more months, put out a basic HTML
mode first, and forever make future deprecations that much more stomachable for everyone?