I've always thought that the lack of anti-senescence technology (which is very common in modern sci-fi) in star Trek to be pretty anachronistic too. People in the 23rd and 24th centuries should be regularly living for 200 to 300 years *at least* - and looking pretty young through most of that! Same for the lack of bio-cybernetics, and the rarity of AI. And the lack of gengineering as well - though at least there is an explanation for that.
Even simple things like cryogenically freezing terminal patients until they can be worked on later, are missing from Trek. And I don't necessarily mean for long periods...but people who die suddenly, when maybe the resources of a starbase or just the doctor having more time to develop a treatment. It's like death is not only considered natural in Trek...but almost...sometimes...like something not worth fighting against too hard.
But with the tech level in Star Trek, the lack of any post-humans/trans-humans is a bit...backward. for all the magical technology that they DO have, In many other ways it like the Federation is a big...Luddite. Not just technologically, but socially too. Their society and institutions and values are very 20th century! People in the 24th century are really just people in the 20th/21st but with FTL spaceships and transporters. Where are the group marriages? gay marriages? Etc...? Gene Roddenberry tried to introduce a "futuristic" social sensibility in the TMP novelization and in early TNG episodes (Troi's comments about marriage to her mother, male creweman wearing skirts - not as a transgender thing necessarily, but just that fashions have changed in 300-400 years) but those were dropped, and by Voyager's time, Tom Paris and the rest pf the crew in the 24th century weren't all that different from Enterprise's crew in the 22nd century - or us here now in the 21st...
But I guess you have to consider the time Trek was created in - even TNG. But compared to people and institution and societies in modern written scifi - by authors like John Varley, Greg Egan, Ken McLeod, Iain M. Banks, just to name a few - Federation society seems pretty...stagnant and conservative.