About 20 years ago I was in Portugal and remember it was a TGV project that didn't take off. It was supposed to connect to Madrid I believe. I imagine that politics and money created this issue.
That keeps being discussed and filling pockets from politicians and their close friends.
We could already have good connections with Alpha Pendular trains, it would be a matter to extend and improve existing infrastructure, not build a new one from scratch.
Same goes for the never ending story of the new Lisbon airport, it will make very happy everyone involved into its construction.
The connection to Vigo happens a few times a day, with regional trains, and to Madrid it is at most twice a day, if it runs.
Then the regular CP strikes, delays and canceled trains.
It isn't by chance that most families have cars, if we rely on trains and bus alone, better have enough time for travelling by land.