What lenses do we need?

A zoom is a convenience lens where you trade off size and speed and perhaps even some image quality for just carrying a versatile lens.  But it does not get into the nooks and crannies of needs as much as the less versatile dedicated prime type lens.

Good old "Mr Average  Zoom" does more things "sort of" well but fails in the nth degree.

So the whole question is in the "how long is a piece of string" category and hinges on the definition of "need".

Does need mean "absolutely necessessary" in which case a kit zoom might be all that 90% of users really need.

Does it mean "think that we need" in which case it opens up a whole can of needy worms.  Usually a subset of the gear acquisition syndrome which morphs into "collection".  The symptoms are first buying a common or garden camera body fitted with an  average but quite respectable kit zoom lens of a certain focal range.  This then creates a need for another kit zoom lens, or lenses, to fill in the focal ranges the first did not accommodate.  Then we might need a fast lens for midnight portraits and a fisheye just for fun.  Further away needs a telephoto that can be used hand held without causing blur, and so it goes on and on until you suddenly realise that you have overcome your gear acquisition syndrome and become "a collector" of miscellaneous lenses.  But at least you have a lens for every occasion if only you have humped the lot along with you or have been prescient enough to have selected well from the lens rack before you walked out the door.

Zooms are better these days but you can pay a lot of money to get the good one you really need.

But if you have become a collector then heaven exists on earth even if most of the time the lenses don't make it out of the cupboard on expedition - at least it is there if you ever need to use it.  Usally there and not with you at the time.