Oh boy! I get to talk about how I hate JRPG's for being a mess!
So first of all, the combat in these games is essentially a puzzle at the high end, at the low end it's basically a time sink to press confirm on attack several times over. Again, as DanVzare said:
If it doesn't do damage, it goes in the bin.
Because ultimately using a status effect is a whole extra lot of time and in the majority of the time wasting fights you would rather not use resource in, it's a pain in the ass to go into the magic menu, select stun, watch the effect maybe miss because you didn't know its only 20% accurate and then proceed to just select attack a whole bunch again because it's a random encounter.
That's probably one of the main issues with JRPG's, because people are playing them for the story and not the combat puzzle, most encounters you go into without knowing what the status effect really does and who can even be hit with it. Shin Megami is often okay with stuff like that, but again there's often better options to kill an enemy with.
Stuff like poison and things normally hit you harder because the game has a chance to whittle you down over multiple encounters while you are focused on ending the one you're on so the next one can pop up.
A lot of JRPG's also don't have the same level of variation in combat as other games do, so a DOT is just that, damage over time and if it does less damage over that time than it would to just hit them. Not great. In other games a DOT might put additional pressure on the enemy because now they need to think about the damage they might be taking. JRPG's often no, just take your turn and don't waste too much time so you can get to the next story beat.
To go back to status effects, they dont scale. JRPG's often have leveling in them to make yourself stronger and if the status effect isnt going to get stronger, its going to be out scaled. This is especially bad in a JRPG because leveling is so important in them and again, not much variability. A stun is a stun, there's turns, no movement, no positioning. Just health bars to beat down to 0.
I feel the problem with a lot of JRPG's is they just approach combat all wrong, it's a chore and mostly not fun. A few games get that they're puzzle games really like the FFT series, or in pokemon's case a PvP game where they can mix things up.
So that's my rant that's not formatted very well at all, it's been a long time since I got deep into a JRPG and it seems a lot of the re-releases push towards making the games easier or just be an action game.