I normally find turn-based combat really boring but I find Shin Megami Tensei games so engrossing in part due to the combat. You need to pay attention to mechanics and properly prepare for each boss fight if you want to overcome them. It’s not about just gathering enough exp. Do you know any games similar to SMT when it comes to gameplay?
imo it’s worth it to play the megaten spinoffs in general, just like what helix said in another comment here. In particular I would like to recommend Devil Survivor because of a lot of things: has a skill steal (skill crack) system so you progressively get better skills for yourself and your demons, makes you think about how you make your team, the first game has the best alignment ending choices in the whole megaten series, the demon auction system, and more. Also: Octopath traveler and its sequel are good