Fallout is based on an alternate version of history. After the bombs that ended World War II for all intents and purposes, Fusion was explored in much greater detail than we have. Fusion cars. Fusion powered robots. Fusion powered wrist computers. History diverged at that point.
The reason Fallout was so similar to the 1950's is because society stagnated at that level, the tech that came out reinforced that level of existence with some modifications.
We also only see one aspect of the world, the United States. We don't know how the rest of the world evolved in Fallout.
Meanwhile, I don't mind wireless rules in ShadowRun, but, I always feel that wired is the most secure option other than someone physically cutting into your line it's hard to intercept in general, which is why they kept it around. That and there is zero noise on a wired connection.
I don't mind a wireless and wired mix, my only problem is that 5th edition was like, no more wired, at all, really.
Mostly though it's about Karma and the dice mechanics. I dislike them. Karma Pool trumps everything in the standard 3rd edition ruleset. Edge is not so powerful.
4th had the problem that you could literally create someone with practically zero possibilities of advancement beyond delta grade ware or similar, your dice could be capped from the very /start/ which meant there was no upwards mobility in a lot of ways.
5th fixes that issue, but introduced the nanovirus that is re-writing people's brains, which is a story element I absolutely hate.
My idea game would be a 2052 set game, story wise, using 5th edition rules. With no Technomancers... which opens up a whole new can of worms. Technomancers are a great idea, but in practice are weaker than deckers. The only way Technomancers stay relevant is their sprites, which catapults them straight to broken power levels if used intelligently.
Regardless, I hope you guys who have fun with third, continue having fun. I had a lot of fun on Denver when third was still relevant, but I can't go back to Karma Bloat, even with proviso's to limit it.