You certainly can get DOT damage to dish out big numbers, the thing is that it takes time and is overall not worth it. Clarifying: an account that has the means to boost DOT damage to big enough numbers probably has many easier and faster solutions to whatever it is facing.

By the way, we'll see DOT damage being useful soon on NA. Imaginary Scramble has some unique challenge quests, and DOT damage is a good way of clearing many of them.

I can agree that it really finds use extremely rarely, but over the years it's definitely found it's uses, every once in a while.

One almost every nero fest, certain challenge/story questts.

The problem is that just doing more damage before you get killed is a lot more efficiet, especially in times when bosses commonly one hit you.

I still have hope it will one day be boosted some, as I like using DOT in any game. I think they could do more with it than the generally mid passive damage we have now.

DoT is always awkward in turn based games

It's probably not a good idea to make DOT damage desirable in general. Let's say they release a broken DOT support that shoots DOT damage through the roof. Now, every boss, for the rest of the game, will need to have a way of countering it - either through spamming debuff cleanse or reducing DOT damage taken. The first solution would fuck any servant that relies on debuffs. The second one would generate extra work to them for, arguably, little benefit.

It is a pretty underwhelming to near useless effect. It is only useful to proc other stronger effects. Almost every case it has a use it is very contrived and in your face. Like woah who knew pierce invul is good against the Ibuki boss fight, that kinda in your face. Even when it has some amount of use it is always out classed. You could give a servant dot spam for an np effect, or you could give an attack up before nping, dealing more damage faster and easier. Even when procing other effects it has nothing to do with dots as a mechanic, you just apply the debuff once and get a bonus.

It inevitably outclassed because it never developed to begin with.

DW and Lasengle, TM too seems set about "DOT is just flavor" as well.

Just think of it as lore segregation that top-tier Servant doesn't bother with curse whatsoever compare to low-tier ones like Diarmuid and Gilles.

It's like stalling. Even with a handful of good stalling servants, the first answer to 99% of the content is still min-turn unga bunga.

Best DOT I can think of is from Pokemon when I'd use Toxic, which is poison damage that increased gradually per turn. Combined with Fly or Dig, a stalling move, it was a top-tier move for getting through the game with under-leveled Pokemon.

If they introduce a status effect like that in FGO it could be invaluable for stall teams.