One critique I hear about Traveller (and other old school era Sci Fi games, to be totally fair) is that the technology is dated, based on 1970s expectations of futuristic technology and unable to keep up with rapid advances in computing, robotics and other applied sciences in the nearly 40 years since the game was first published.
I imagine the first temptation for most players and GMs of Classic Traveller is to try and shoehorn more advanced technology into the rules, often borrowing from games and sources like cyberpunk to represent cutting edge computer technology, but in my mind, this changes the scope and feel of the Traveller experience too much to be worthwhile.
I prefer to give some thought to justify why the OTU has the technological standards that it does, so that the mechanics of the game remain unchanged, but players can accept the tech level of their campaign as plausible. Here's a few thoughts on specific technological topics:
In the 1970s, when Traveller was written, even the home "microcomputer" was a pretty bulky piece of equipment that usually had to be plugged into an equally bulky cathode ray tube television set. Opening the computer's case revealed a series of circuit board "cards" that plugged into slots on the main board providing and expanding many of the system's functions. Those circuit boards were familiar to anyone who took high school electronics shop class or spent their hobby hours hanging around the local Radio Shack talking transistors with their fellow radio geeks. I mention Radio Shack for an important reason. While you could very easily go buy an Apple II or Commodore home computer that came, essentially, ready to use, Tandy/Radio Shack's systems often came as DIY kits, with the buyer expected to have the electronics basic skills needed to assemble the device according to their needs. Anyone with a modest workbench and selection of basic, cheap tools could build, and more importantly, repair, their TRS80 (Tandy - Radio Shack, get it?)
When you are hurtling through space, light years from the nearest repair facility and restricted by practical matters of available space on your ship to a fairly basic selection of tools and spare parts, you need to be able to fix things yourself. "Old school" computer components, such as the circuit boards I mentioned above, can be assembled or repaired with pretty basic tools: wire snips, screw drivers, soldering irons and a handful of spare resistors, transistors and wire. An engineer PC is expected to be able to fix most problems with the ship's computers with little more than these parts. Keeping computer component technology at the levels given in the game makes this plausible.
Even today's state of the art computers have reached the point where they are no longer user serviceable, if your iPhone malfunctions, you send it off to some mythical service center where they use expensive, high tech tool to fix it, or more often, replace it, since that is often cheaper than fixing the broken unit. This service model is completely unworkable on a small starship. The bulky advanced equipment used to service micro and nano technology is too big and expensive to build into a ship's engineering room, and what happens when that equipment breaks?
For many similar reasons, advanced computer programming is unwieldy and inconvenient for the crew of a small starship. Where most computer programs could be coded or troubleshooted by anyone with a basic education in programming and a bit of time to go through the code in the 1970s, today's programs are complex and often generated by other programs to a user's specifications. If you're the computer tech on a starship and the software gets buggy, you need to be able to troubleshoot it quickly and easily before your life support, drive controls or weapon systems go offline.
In our "After the Rim War" campaign, we also retrofit the Traveller: The New Era ideas on Virus into the setting's history, as a minor contributing factor to the onset of the Long Night. Complex, integrated systems are a hacker or intelligent virus's dream, while simpler, isolated and dedicated programs make those cyber attacks less effective and easier to combat. Since the Long Night ended and the starfaring races recovered from its horrors, it is very rare for computer builders to interconnect every system on a ship with arcane and impossible to troubleshoot computer programming.
The previous two points on hardware and software pretty much explain the reason cybernetic gear doesn't permeate the OTU setting. If your cyber-arm's metallic frame breaks, who can repair it out in the field? If you suffer brain trauma and the programs controlling your cyber-eyes go buggy, who can plug in and troubleshoot the code?
Another major point is the assumed cost of these devices. How many average citizens can afford this gear? Sure, wealthy nobles and merchants probably get fancy cybernetic items installed in order to flaunt their wealth, but 99% of the folk you meet while Travelling simply can't afford the stuff, especially when life extending and enhancing drugs and medical treatments can achieve similar results much more safely and cheaply.
I think it's fun and cool to have the PCs encounter really high tech gear now and then, but that's what the tech level mechanics in the game are for. My players will run into TL15+ worlds once in a while, but overall, I'm going to keep things in the TL10-12 ballpark.