Warning: SPOILERS for Star Trek: Picard's Season 1 Finale
Humans can live a very long time in golem, a synthetic body, so Jean-Luc was quickly resurrected. But while Picard was certainly in the twilight of his years, he was still quite a ways from reaching the end of the average human lifespan in the 24th century.
In Star Trek's optimistic future, Earth has been transformed into a near-utopia and this has had a positive effect on the human race and the average person's lifespan. By the 23rd century, humanity had wiped out war, disease, hunger, and the desire for money to instead concentrate on the betterment of the individual and of the entire human race. While there are still Star Trek movies, it wasn't unusual for Captain James T. Kirk (William Shatner) and the crew of the Starship Enterprise to be saving the galaxy in their 60s. In fact, iral Jean-Luc Picard was 80 when he quit Starfleet; if he hadn't abruptly retired, Picard likely planned to spend the remainder of his life in service.
The average human lifespan in Star Trek was approximately 100 years during Star Trek: Enterprise's 22nd-century era. By Dr. Leonard "Bones" McCoy (DeForrest Kelley) was 137 years old when he cameoed in the Star Trek: The Next Generation premiere episode, "Encounter at Farpoint."
Of course, there are cases where humans have lived longer than 137 though various means, usually because of strange anomalies encountered in outer space. U.S.S. Enterprise-D, he was technically 147 years old (although physically, he was only half that age).
There's also the strange case of Zephram Cochrane (James Cromwell), who was born in the 2030s, invented warp drive and initiated Spock (Leonard Nimoy), and McCoy met Cochrane (Glenn Corbett), who was aged backward into a much younger man by an alien being called the Companion, despite the inventor of warp drive technically being over 230 years old in the TOS episode "Metamorphosis".
Thanks to all of their 24th-century advantages, humans live longer than ever in Star Trek and they've caught up with the lifespan of the Klingons, who can live over a century (although most Klingons prefer to die in glorious battle and never see old age). Still, humans have a long way to go if their lifespans are ever to match the Vulcans, who can live up to 200 years. But at least human beings in Star Trek have taken the old Vulcan greeting "Live long and prosper" to heart.