Final Fantasy Tactics is still the greatest game ever made.
Fell Seal has been fun, and the recent addition of monsters is impressive, but it was too soon after my first play-through for me to keep at it.
Working on my 2nd playthrough of Fire Emblem Three Houses right now, went Golden Deer the first playthrough since it seemed the most like Tactics story, and I hear I already played the best route so my motivation to cover the others has fallen off significantly. (mostly I just want to kill Hilda) I still find myself trying to plot out units as if I can mix and match like Tactics, then I get a few battles in and remember many tactical games don't like to let you have fun. (I just want Fortress Knights casting magic, even if they're bad)
Disgaea 5 on the other hand has provided many hours of gameplay, including skipping every single piece of dialogue possible since it's so cringe. I can't complain about a game with so much customization options and a twin-headed Dragon though.
The Ivalice Alliance
A Final Fantasy Fan Guild