Apple Business says: There’s an error; You’re either on an unsupported browser or viewing this site on a mobile device. Switch to a supported browser.
https://business.apple.com
https://business.apple.com/abm_unsupported_browser?reason=Browser%20Type
https://support.apple.com/guide/apple-business-manager/program-requirements-axm6d9dc7acf/web/
An Immigration Attorneys' company says: Unsupported Browser; Our platform is designed to work exclusively with Google Chrome and does not support other browsers at this time. Please set up /log into your Alma account through Chrome.
https://app.tryalma.com/sign_up
https://www.tryalma.com/
but not from https://app.tryalma.com
Nothing reachable from https://www.apple.com/ seems to fail on Firefox.
So the story isn't really about firefox.. it's about Chrome's marketshare being high enough that some companies are happy to ignore every other browser.
That's about where IE 6 and then IE 11 were when everyone was excited they could finally drop them. Why should anyone treat Firefox differently?
1. IE was the default browser for many users (i.e. anybody using Windows who didn't know better).
2. IE had a lot of bugs and and was often non-compliant with standards.
Those two things combined meant that supporting IE required additional work, and if you didn't put in that work you were going to get users from IE anyway they'd just get frustrated and confused when things broke. So "detect IE and tell them use something else" was at least a reasonable fixed-cost approach to not having users get totally stuck. (And IE went down to 2-3% at least in part because devs revolted against IE earlier and started serving those "don't use IE" messages when its usage was still higher.)
Neither factor is really true of FF. It's not the default for any major platform, its user-base at this point is largely power users who won't be easily confused, and outside of some non-standard APIs most sites don't need and some fairly edge-casey stuff, most sites that work on Chrome will work fine on FF as well without alteration. If anything, IME Safari is more likely to need special attention than FF (but of course Safari has much higher market share so it merits that effort).
So I totally get not wanting to spend QA budget on FF, and I could understand showing a small banner suggesting you use a different browser, but erroring/completely blocking usage of the site does feel excessive to me, and even a bit mean-spirited since it takes extra effort to detect FF to show the message and prevent using the site! I don't think these sites are going out of their way to block usage of other low-usage browsers (some of which can alter behavior that could break some sites even if they are Chromium-based).
These are just lazy developers, or developers who don't want to bother testing against FF. It happens. Move on. This is not some industry trend.
The problem is that the value of doing it is essentially none.
Be the change you want to see
Vote with your wallet
These are all sayings emphasizing going out of your way for a social good. This is just more of the same.
As someone else said here, we should probably chalk it up to laziness on developers' part; maybe there's more to it, but I'll take that explanation and move on :-)
[1]: https://addons.mozilla.org/en-US/firefox/addon/uaswitcher/
Also, developers at many companies don't own their time. They're given a certain amount per feature that they didn't estimate themselves, and the company doesn't give them time to fix Firefox specific bugs because it would cost them more than the user's monetary value is worth compared to other features or bugs.
The developers are lying and trying to force people to switch browsers.
I only use Chrome for Microsoft Teams there NASA insists on using (Teams doesn't seem to detect my camera in Firefox... And the teams for Linux app was total trash when I tried it, maybe it's better now if it still exists.). Is there a way to stop it's obnoxious trying to be the default browser every time?
For what it's worth. I agree with OP which is why Firefox with uBlock Origin is my primary browser.
The business case for things like this is pretty obvious when firefox usage is so low.
I love firefox, i've been using it since version 1.0 to today.
However mozilla really has been directionless, its no surprise that nobody cares when the browser has basically devolved into copying everything that chrome does, but a year later and not as good.
In my first job back in 2019, a support ticket came back about a dropdown bug in Firefox. It didn’t even make it to engineering before they told them to switch to Chrome.