Completely false.
The very first video game(s) ever, are "action" games. Turn based gaming is not a limitation on computing, and never has been. To think so shows complete ignorance of software. And violence/killing far predates organized games requiring thought and the taking of turns, if you really want to get into it. There is nothing whatsoever more "modern" about action, fighting, what have you. I don't think one is inherently better than the other. They are just choices with their own trade offs.
If Sakaguchi said he thinks FF16 is the pinnacle, I'm pretty sure he is just being gracious. Kind people are like that. And your comment that all the games would have been this way from the beginning, if it were possible, is an assumptive leap. It was a role playing game, taking its queues from table top games. It's a style. FF16 is also clearly not even close to the best game in the series, as someone who has been playing almost all of them for the last 30+ years. FF16 is such a mindless slog of a game, there is absolutely nothing more "modern" or advanced about it than any of the previous FF games except production values.
Back to Starfield.