As a relative layman who's still played a number of classics, I'll call BS on that. J-RPGs, by and large, have always had serviceable writing at best, even the old ones, and many of them are essentially anime trope-land. Good writing in games in general is a fairly rare occurrence. Not every game is Fallout 2 (first example that comes to mind), far from it, especially in the realm of J-RPGs. I have enjoyed the story of some J-RPGs, but I've never played them for their writing, I'll tell you that much.
Also, let's not act like Octopath doesn't bring its fair share of modern systems and innovations. Its combat system wasn't the norm back in the day (beyond being turn-based), same for its story and character progression. Like yeah, there's Live A Live and... what? And it might be 2D-inspired, but it's drop dead gorgeous, using the latest engine and 3D effects. Just because it's got pixel art doesn't automatically make it a nostalgia-fest.