I mean, the problem is that it is technically worth casting, it'd be a massive failing on SE's part to make it so underpowered that using a few seconds to cast it is actually sub optimal compared to just casting something else, but with how the mechanic to actually cast it works, it's damage doesn't feel worth all the hassle, even though mathmetically you should be doing it to maximize your damage. It feels like a meal you have to spend hours making only to realize when you finish and actually eat it you really don't like it, but you're stuck eating it anyway.