I've always felt as though I'm unable to fully enjoy RPGs. Final Fantasy is one of my favourite series of games, but outside of that it's pretty limited. Undertale was probably the last RPG I played that I liked, mostly because it did something different with the combat system and the puzzle aspects weren't too over the top. I feel the same way about CrossCode, but I would put that game into a different category as it isn't a traditional RPG.
I just don't want to sink a ton of time into a game that is mostly a grind with story elements and payoffs that are few and far between when I could play a different kind of game that is at least continuously stimulating.
Illusion of Gaia is second in and the "Trilogy" is only loosely tied with the same themes. There are no real story ties. You aren't missing a lot with SoulBlazer anyway. It's like the original Zelda 1 compared to Zelda 3 as far as polish goes as well.