Companies like chrome because it’s the most used browser. So if they develop for it, and only for it without caring of compatibility on others, then it’s cheaper. And since they don’t want you to use another browser and complain that their site is broken, the just block you.
Which is kind of dumb, because if you target Firefox you are writing to a standards compliant browser that means your code should work on all other browsers. Chrome came when IE still owned the internet and their goal was to offer a faster browser that still worked, so now chrome has a bunch of hacks coded into it.
Devs don't always get a lot of choice when the upper management thinks chrome is better
The devs can tell management they'll make it work on Chrome while really making it work cross-browser. It's not too hard to make a site cross-browser these days, except for Safari sometimes having weird bugs.
Pfft, who would do that? As a Firefox user myself I never would. Carve out a bit of time on the down-low to enhance cross-browser support on a website after management shortsightedly told me to just block anything other than Chrome? No no no! Not me!
Of course as others here (including you) have pointed out, it's much less of an issue these days. Though it does still happen, it's nowhere near as bad as the IE days (that browser can burn in hell for all eternity!).
Well chrome should, yes. But they don't.
Then some JavaScript framework developers think "well this non-standard feature is neat, let's use that everywhere" and then companies who use their framework (or a framwork dependent on it) can't support all browsers.
It's a multilayered problem (as always) with lots of individually decisions that make sense, but don't work out in the end (as always).
I think the most annoying thing here is the decision to blanket ban other browsers. Why not just have a little drop-down bar at the top that says 'You may encounter issues, we recommend browsing this site with Google Chrome', instead of completely blocking access? The cynic in me suspects it's linked to advertising.
If one changes the user agent in Firefox so that it announces itself as Chrome, most of these sites work just fine. Adobe Express is the last example I tried.
Doesn't have to be, some features are only available in certain browsers (usually Chromium). For example AFAIK Chromium is the only browser that allows you to connect in the browser to Bluetooth devices, its the only browser that can access for example a phone's NFC chip or that can interact with USB devices.
That’s my point. Example, meet Sarah. Sarah goes to www.megacorp.com to pair her new MegaDevice via NFC. She gets to the pairing page and there’s only a small banner that tells her her browser may not work. She doesn’t see it and starts the syncing. It fails repeatedly. Her first thought will be “O.. Mygod! mergacorp’s website is like, so. Broken!”
Now example B: Sarah goes to the website and sees “WRONG BROWSER, use chrome instead” on the screen in big. Now Sarah thinks “Oh, I’m stupid, it’s my bad, I should use Chrome instead instead of Firefox. Firefox is the worst”.
Then end.