The mobile phone is actually Older Than They Think, though, especially in the form of a "car phone." While expensive and limited in many ways, commercially available car phone technology dates back to the late 1940s, often with radio used to contact an operator, who then would patch the call into the regular phone system.
An episode of the 1950s TV series showing Paul Drake using one.
There is also the matter of smartphones become common devices; with data service becoming common on top of voice/messaging service, looking up information online can done near instantly where wireless data service is available.
A Long Runner might even have its earlier episodes/books/etc.For comparison to many of the numbers below, Earth's population is 7.4 billion and climbing as of this writing.It should be noted that some of the agricultural technologies depend on petroleum and other materials which can soon run out...The important qualifications of this trope are as follows: For the most part, once a technology is invented, it tends to develop at warp speed.Remember, it took only about 65 years (1903-1969) to go from one rickety plane barely able to get off the ground to putting a man on the MOON!Contrast I Want My Jetpack, where the writers The widely available cellphone is a major Trope Breaker, leading to many clumsy explanations for why cell phones don't work in particular circumstances.