Star Trek: Vanguard is the story of a space station, situated at the very beginning of The Original Series. Kirk even has a few lines in the first part.
In the story Starfleet explores the awesome technique of the Shedai, a god-like species that have fallen in sleep eons ago, and are revived by Starfleet exploring their artefacts.
Why do these events (they eventually manage to understand the origin of the power of the Shedai) have apparently almost no influence on the Picard era?
A lot of the info seems to have been classified as too dangerous for people to know about.
Clasping his hands behind his back, Akaar replied, “While the Shedai and our encounters with them are public knowledge to anyone who’s read a history book, much of the information we’ve obtained about their technology and capabilities, particularly their so-called meta-genome, is shrouded in secrecy. Likewise, the official project files from the Starfleet effort to acquire and understand Shedai technology are still classified.
and
“I know the situation is grave,” Bashir said. “And whatever help the Federation could have provided to the Andorian people, it should have, of course. But my understanding is that they did do what they could, that nobody in our government, from the president on down, even knew about the Shedai genetic information.” A century earlier, Starfleet had apparently discovered a massive, complex genome in the Taurus Reach, created by an ancient civilization known as the Shedai. Deemed too dangerous even for general research purposes, the entire catalogue of genetic information had been classified.
and
After everything that had transpired during Starfleet’s all-but-disastrous attempts to understand the Shedai and the awesome power they once had commanded, someone within the Federation hierarchy had decided that the entire project should be buried and forgotten, citing the potential for unchecked abuse should such knowledge fall into the wrong hands.
Though Starfleet had shoved the collected data and materials into the depths of a classified archive facility and consigned almost everyone who had survived the operation to relative obscurity, other parties who had acquired information and understanding into the Shedai continued to perform their own research.
Which seems a bit of a cop-out, but there it is.
