'Standard zooms' are the most common lenses around, due to many version being bundled with cameras and becoming 'kit' lenses. In my early film days it used to be a 50mm f/1.8 or f/1.7 that came with that new camera, but for some time those have been replaced by zooms. And in many cases, people never buy another lens. They don't get much attention, unless they have a fast aperture, but I suspect that the majority of images taken on interchangeable lens cameras are with a lens of this type. So this type of lens with this type of coverage must have something going for it.
I currently have three. The 24-85mm f/3.5-4.5G Nikon lens, 16-50mm f/2.8 Fuji Fujinon X lens and 12-40mm f/2.8 Olympus m.Zuiko m4/3 lens. So are they my most used lenses? And if so why?
NIKON 24-85mm f/3.5-4.5
OLYMPUS 12-40mm f/2.8
FUJINON 16-55mm f/2.8
These three 'standard' zooms cover three sensor sizes and it's interesting how close they are in terms of results when the aperture is adjusted to give similar depth of field. For me, the m4/3 advantage shows up quite nicely here. The same result at a wider aperture and therefore a higher shutter speed. The three cameras have a somewhat different idea for what constitutes average white balance however and levels of noise reduction are different. In all cases processing from raw gives a better result but again they are very similar.
The Fuji and Olympus have wider apertures and are therefore 'faster' lenses, but of the three the Df has the better higher ISO performance so the speed of the other two lenses is somewhat cancelled out.
In use the lenses all focus very quickly and I find it impossible to say which is the quickest. The Nikon is the oldest lens by far and hasn't been made for years, but it still produces excellent results, which is no real surprise. It is a Nikon after all!
These are certainly superior to your average 'kit' lens and though the Nikon was probably intended as that, it has always been regarded as a quality lens. Some have even asserted that it's just as good as the current Nikon 24-70mm f/2.8. I certainly find it superior to the current slower 24-85mm with VR stabilisation that Nikon bundle with several cameras. I don't have one anymore but I was always having to add sharpening to compensate for the soft results. However, mention of the 24-70mm f/2.8 'workhorse' lens shows the advantage of the Fuji and the Olympus, as both are smaller, lighter and cheaper than the Nikon monster, with the Olympus being especially compact for a lens of this speed. Once again a m4/3 advantage.
I've already written several times about how much I like the Fuji 16-55mm and the Olympus 12-40mm is close behind. And I do use these lenses and these focal lengths for a lot of my work. I would estimate that I use this range for about 75% of the pictures I take. around 15% for wider options and 10% for narrower, telephoto shots. So it's clear that the focal range these lenses offer is very useful for me. Of course, a sports photographer would have a completely different set of priorities and we've all seen those monster lenses at televised sporting events.
But for my kind of travel, landscape and location work the 24-85mm ('FF' / 35mm) zoom is perhaps my most useful and 'go to' lens. It's also nice that these days, these lenses offer a slightly longer telephoto end and are wider than the 28-70mm ('FF' / 35mm) option that used to be commonplace. And over the years I've seen 28-70mm become 28-75mm then 24-70 and 24-75 before ending up where we are now.
And due to the faster nature of these lenses over 'superzooms' it could be argued that this more conservative range is actually more useful that something like a 28-200mm or 28-300mm. ('FF' / 35mm) Certainly once I got the Fuji 16-55mm I stopped using the 18-135mm almost overnight and it's now for sale on ebay. Because no matter how attractive that very large range may appear, it is always a struggle at the long end to balance decent hand holdable shutter speeds with an aperture that gives a decent performance. I'm sure I'm not alone in finding that too often I'm using zooms like that at the maximum aperture, which is usually the poorest quality. In fact it's often the case that I will crop from the shorter zoom and achieve only slightly inferior quality and in some cases that quality difference is pretty much unnoticeable.
So yes, I would accept the premise of the question at the top of the page. These are pretty much my ideal lens. And despite my liking for them, I do use prime lenses a lot less. I always seem to be attracted to primes, particularly the 'fast ones' but it's interesting how often I spend a lot of time testing and comparing them (and enthusing about them of course) but end up taking a zoom out with me when I'm shooting 'for real.' And I wonder how often others do the same. Because the 'kit' zoom range isn't there by accident. Camera manufacturers are fully aware that these are the focal lengths most people use in most circumstances and I'd be prepared to bet that standard zooms sell in significantly larger quantities than telephoto zooms, for example.
And I'm old enough to remember the days when zooms in general were regarded with both suspicion and often disdain. And yes it's true that they are still a compromise between usefulness and quality. But that compromise has become less and less over the years and these three lenses show exactly why that is the case. And I've love to see a few lens 'snobs' try and spot the difference these days between an average prime and a decent zoom, without knowing which was which.