I have 10 to 15 family members in their 80s and 90s who use FB. A group has been set up for them, and they post photos and comments, and they chat with each other using Messenger. These are people who don't know of and honestly don't care about the difference between the internet and the web, and to them, "The Internet" simply is Facebook.
Using the tech is already hard for them. Some are partially sighted, some have mobility issues, some have arthritis, all can easily use FB to stay in touch.
And they don't use anything else.
It's just not an option to try to get them to change, it really isn't. Please, please do me the courtesy of accepting that I've done the analysis. Many times. It's simply not a reasonable objective.
And no, I won't squat on someone else's FB account so I can stay in touch.