Heinlein's Future History celebrates the social impact of technological change. As such, it celebrates the world in which Heinlein lived and in which we live now that some of our year dates correspond to those in the series. It is to be hoped that we will have a, beneficial, "Revolt in 2100," if not sooner.
Although Heinlein anticipated future changes, we are already living in a technologically changed world. This has been true since the beginning of agriculture and increasingly true since the seventeenth century. Imagine that we inhabit a fictitious future history written in 1900 and read by people who really expected their pre-1914 regimes to survive till 2014 or later.
Heinlein shows the impact of technology on daily life, economics, politics and popular religion as well as the political and religious misuse of communications technology. Much of what he describes is paralleled in the real world. No one lives on the Moon yet because, despite the arguments of Heinlein's character, Harriman, and of Heinlein's successors, Anderson, Niven and Pournelle, the capital expenditure of space travel is too great in relation to any perceived profit. The US seems to have raced to the Moon to develop rocket and computer technology for use on Earth.
We are not in contact with any Martians or Venerians, which are in any case marginal in the series. These were science fictional props that were not necessary for Heinlein's speculations about rocket technology although he did expect contact to be made with Martians. Despite the existence of other intelligent species in and beyond the Solar System, the Future History becomes mainly an account of the future of humanity comparable to works by Wells and Stapledon.