This article by Lauren Weinstein isn’t just applicable to the elderly, but to anyone who doesn’t have the money or expertise to move to a newer OS / browser.
I’ve seen this attitude expressed a lot over the years: sorry, we’re no longer going to support your system that’s still working OK, and we’re not going to do anything to help you, so suck it up losers.
And, more often than not, the reason for software developers dropping those users is due to factors of the developers’ own making. Build-up of bad code, leading to bugs and security issues. A lack of motivation to update their codebase. Or just a cold calculation that there’s not enough users of that system / version to justify worrying about them.
Good web design should degrade gracefully according to the capability of the browser, as well as network conditions. That’s not just good for people with older devices or browsers, but also folks with slower or less reliable Internet access.
There’s a good argument to be made that software design should be the same. In most cases, your application should absolutely be aware of the user’s accessibility challenges or the capability of their device, and adjust accordingly.