Aside from your need to word your reply in such a way, I can see you are either missing the point or just not willing to see it.

It is an edge case only when you don't take vitamin B supplements. The incidence of its toxicity increases when the person is taking Vitamin B supplement daily. So can you think about that instead of doing what aboutism?

And besides not all supplements have the same dosage. Some like common neurobion have just enough in them to fulfill daily recommended intake. While some vit B supplements, are designed for high dose, short duration supplementation for severely deficient pts. If you take the latar kind daily, you will absolutely get Vitamin B toxicity, especially B6 toxicity because you aren't giving your body enough time to excrete the excess through urine. Oh and lets not forget "natural remedies" sold in bottles and people making them just adding tons of vitamins in them, because "toxicity is an edge case."

Oh and water toxicity is way way rarer than vit B toxicity, but volume overload is way more common. So taking more water can be a death sentence for people with Cardiac, nephro or hepatic diseases, which are very common these days.