Some automobiles can park and/or drive themselves now. They also have GPS devices and they are faster than the ones from the 60's.
And that's just the point - nothing has changed! Despite these meaningless tinkerings, the automobiles do not
behave in any way differently from how they behaved in the 1960s. The higher speed doesn't manifest
in any way, the auto-parking feature doesn't change anybody's lives; the problems and strengths of automobile traffic are the exact same regardless of this so-called "development", because even when the "development" attempts to tackle problems (and this is extremely rarely), it amounts to treading water.
Economy isn't better because individual cars have better economy - the improvement is meaninglessly small and automatically compensated for by higher fuel prices, largely brought on exactly because cars spend less. Accident rates don't go down because of safer cars, because there are more of them, being driven more recklessly. It doesn't make any difference whether your entertainment comes from the local FM channel or from a USB library. And so forth.
My point is, you have no idea what discoveries or innovation could have happened in those 8 years. It can't be predicted, regardless of political climate.
True enough. But we hear of none that would make starships faster, and that was the point being brought forth: that the Romulan Neutral Zone went from being far away to being not so far away in those eight years, without anything explaining the change
. No other parts of the galaxy suddenly moved closer to Earth, so a change in starship speed doesn't serve as an explanation here.
On the other hand, there's no particular need to worry about this. Even if the RNZ is behind a long commlag in "The Defector", and it only takes days at most to fly from there to Earth in ST:FC, these things are not in inherent conflict. It might just be that this area of space enjoys poor communications (Romulan jamming?); it doesn't follow that it should be far away in starship-hours!
As for ST5:TFF, if we explain the travel to Sha Ka Ree with Cytherian technology, then it's easy to argue that going to the center of the galaxy takes decades. It's not as if "Magicks of Megas-Tu" would have featured our heroes actually going
there. They just observed the center, for which it should suffice that they get a good vantage point - quite possibly tens of thousands of lightyears distant from their target.