How many extruders are too many?

[ONUS]

Thought I'd pose this inquiry to this community. Is it really needed to have 4 or 5 extruders on a 3d printer. From what I see, you really don't need more than 2 at anytime for 99% of prints you do. Anyone out there have a 4 or 5 extruder 3D printer that uses more than 2 of those extruders frequently? I'm just beginning to see more and more 3d printers come out with 3, 4, and 5 extruders, which I feel is unneeded.

[Feign]

With careful design, you can make practically anything with one extruder. Without careful design, two extruders is best; one for print material and one for support.

To mix flesible features with rigid ones, having a third extruder is needed (preferably direct mount for flexible filaments).

Beyond that, there's the hypothetical conductive filament... There's better progress with this in paste extruion than plastic right now, but you never know.

Soooo, the most for a practical setup is two bowden, one direct mount and one conductive paste extruder... A setup that would look like Frankenstein's monster.