As for those who are 75-84, those we like to call "middle-old". It's true that most of them were close to retirement when the internet was at its early years, and perhaps they didn't HAVE to learn how to use a computer to keep doing whatever it was they were doing to earn a living. However, those older adults are still active, enjoy living, value the relationships they have with friends and family, and understand that technology can help them stay connected, up-to-date, and maybe even enjoy life more. Those older adults are willing to learn how to use new technology, and are willing to spend on it, as long as they find it useful and that it brings value to their lives (rather than just being a pretty object sitting in a drawer somewhere).
When it comes to 85 year olds, things get a little more complicated. Social circles start to dwindle, widowhood is much more common, health and security issues become a major concern. When it comes to adoption of new technologies- rates drop significantly, and products have to be a lot more enticing and easy to use, for them to be considered a "worthy spend" by that age bracket.
So why don't all 85 year olds carry a smartphone in their pocket? First of all, because it wasn't designed with them in mind. Those 5" screens take quite a lot of dexterity. That's why jitterbug phones are needed and that's why those types of phones are adopted. Tablets are adopted by that age group, because the large screen and large buttons make them easier to use. Voice activated devices like the Google Home and Amazon Echo are also "adoptable", since they require little to no "know-how" in learning how to use them. What could be easier than simply saying: "Alexa, play some classical music"? (only a device that could read your mind).
Bottom line is, older adults want to use technology. But they aren't willing to use ANY technology at ANY cost. I'm not talking about how much it costs in USD (which is a factor in making a purchase decision), I'm talking about the time and energy it takes to learn how to use devices, and about the value those devices bring to one's life. No one would expect a 20 something year old to spend a $1000 on a device that requires them to read the manual every time they want to perform a simple task, so we shouldn't expect 80 something year olds to do it. Gerontechnology should be simple and, well, intuitive.