Technological changes may require that mystery/detective writers make changes to plots, circumstances, and situations that have worked well for a long time. For example, the current ubiquity of cell phones has made it harder for the writer to explain just why it was that Charater One did not simply call Character Two to let them know that Character One's car has broken down and thus their arrival will be delayed. Just a few decades ago such a breakdown might result in Character One having to walk for miles/kilometres on a dark road on a stormy night in order to reach a farmhouse from where a call might be made to the nearest garage. What opportunites this simple circumstance opened up to the inventive writer.
Someone writing a similar story set in current times needs to explain why Character One didn't simply call Character Two (and the towing service) on their cell. (The standard explanation now is usually "the car broke down in one of those areas with little to no cell phone reception.) Sometimes the explanation as to why modern technology could not be used becomes rather convoluted and requires some (or a lot of) suspension of disbelief on the part of the reader.
The Agatha Christie short story Philomel Cottage is a good example of a story that would have be written very differently if it were set in present day England rather than the England of 1924.. In 1924 it was still almost disturbingly easy for people to move from one place to another and begin anew. Even long distance [trunk] telephone calls were unusual (and expensive.) There were no fax machines, no video conferencing, no television, most newspapers carried few photographs and it was highly unlikely that someone in one country would even see a news article that had been published in another country. If someone grew up and stayed in a small town or a closed community then they probably had few secrets from other people in the same community or social circle but it was often nearly impossible to find out much about the background of someone who had lived far away or had been out of the country for an extended period of time. That was one of the reasons why people would actually present letters of introduction (from people already known to the community) when they moved to a new place.
As Philomel Cottage begins Alix King is worried that a face from the past will bring uncertainty and unhappiness into what seems to be a perfect married life. What happens to Alix and her husband over the next few days is an example of Christie in her quietly chilling mode rather than the comfortably cozy mode that most modern readers associate with her name.
In this reviewer's opinion one of Christie's best short stories and well worth the read (or the rereading.)
 The story was published in Grand Magazine in 1924 and then in 1934 republished in the short story collection The Listerdale Mystery.↩