Technology changes all the time, and writers have to keep up with it. This need for change doesn’t just affect our tools and our paths to publication — every so often a change comes along that wipes out or revises entire categories of plot devices and developments.
There was a time when characters could leave town, or leave the country, and effectively drop off the edge of the world as far as the folks back home were concerned. Twenty miles was a long way, a hundred miles was even longer, and across the ocean (or the continent) was gone-for-good-and-never-seen-again. Which was good for sad plots, with lost true loves and all, and good for suspenseful plots, with mysteriously returning missing heirs, and good for providing characters in need of escape with a place to go.
Then transportation got faster, and we got the telegraph and the telephone and the transAtlantic cable, and writers had to deal with the fact that it was now a lot easier for their characters to stay in touch, and a lot harder for them to hide.
The status quo rattled along for a few decades, as far as plots and technology went. There were a lot of technological advances, but most of them weren’t in areas that would require massive retooling of existing plot machinery. Even personal computers opened up more plot possibilities than they closed off.
Then along came cell phones and social media. All of a sudden, it became a lot harder for writers to put their characters in that state of fear and isolation that’s so productive of interesting plot developments. So long as your protagonist has a cell phone — and your readers will assume that he or she does have one — then at least in theory help is just a phone call away. If you want your character to be truly alone and forced to rely only on his or her own resources, you’re going to have to deal with the cell phone problem: lose it, leave it behind, drain its battery, break it, or make sure your readers know in advance that the character’s potential location has cell phone dead areas. (They do still exist, especially in rural or wilderness areas; and even in cities there are some places where reception is at best spotty.)
It’s enough to make a writer turn to historical fiction, it is. Just don’t turn to near-past historical fiction, because then you’re stuck with figuring out the point at which — for example — cell phones went from becoming large, expensive, and rare to being small, cheap, and ubiquitous. (At some point during the run of The X-Files, is my guess; check out the differences between the phones Mulder and Scully use in the first couple of season with the ones they were using by the end.)