They weren't perfected at all. That's an absurd notion. It implies that the development of video game combat systems are linear and quantifiable.
That, and old turn-based games were mostly grind-fests or consisted of hitting [Attack] over and over.
If anything there are countless areas in which the genre can be improved.
They were "perfected" in parts of game design that are
linear and quantifiable, that being hardware limitations, which was the point. Turn-based RPGs were a popular choice in the early years of game design (and continue to be a popular choice for amateur game devs) exactly because they require somewhat less sophisticated programming and resources etc. Anything that would improve the genre gameplay-wise would require lateral thinking and wouldn't be improved by new hardware/software much at all. Would. say, an improved physics engine improve a Turn-based RPG? Aside from making spell effects flashier, probably not (If you got creative maybe you could incorporate physics into how damage is calculated and such I suppose).
The thing you're describing (people mashing attack over and over) isn't something solved by a better console but by a dev not being lazy when they're calculating the stats for the game. So obviously, someone's going to ask why they would spend millions on a major console release when they can make basically that same game for Arcade or RPGM.
I'm not against a big console RPG, I think that's a pretty big reason though. You don't need to release a console game to improve RPGs. On somewhat a related note, how many console puzzle releases have you seen other than the obligatory 5 or 6 a console gets? Most of them seem to have migrated to mobile gaming.