I think the issue here is a notion of "progressiveness." The idea implicit in an argument that technology is linear is that there is something history is aimed at and heading towards. This conception need not be limited to technology. For example one could make (and people have) the same argument about morality or political systems or social organization, etc. This is in my opinion inherently ahistorical and presumes a kind of path that history will inevitably take.

The idea is appealing or seductive when it comes to technology because it seems obvious that (to take an example off the top of my head) you're not going to start with a super computer and then invent the capacitor. But saying that technology isn't linear, or progressive, isn't to say that certain inventions don't lead to new inventions that build on the first thing. Rather it is to say that the developments are dependent on historical circumstance broadly conceived. In other words, which things lead to which other things are contingent historical facts. If we are to take a historical look at technology, we can see that the path of technological development is hardly teleological.

Are you familar with the idea of local maximums? Imagine in a low spot between two hills. You can climb either hill. Regardless off what hill to climb, you are increasing your elevation. But one of the hills will not reach as high as the other.

In evolution, its called a fitness landscape. Paths of technological development can be similar.

A recent question on ask historians involved the development of iron weapons. The answer involved metallurgy - iron is frequently inferior to bronze, and it was only the development of consistant alloys and better techniques that gave iron an edge (a better edge in this case). Focusing on bronze is advantageous - until another civilization manages to be able to alloy a superior form of iron. Local maximums.

One concept that this often appears in is the idea of comparing societies and judging one to be "more advanced" than another. Someone in another comment mentioned the Mayans not using the wheel for transportation. Does that mean they were less advanced than a society that does use the wheel for transportation? In a simple history book, we have a tendency to line inventions up in an orderly way which hides the vast array of factors that affect both the invention, innovation and 'take-up' of an idea. We tend to think that ideas that come later, even if they are unrelated (and even if they are related), are 'better'.

With regards to a wheel, inventing a wheel for transportation relies on other factors: for example, the geography in which the society lives. To reduce this to simple factors, a hilly, rocky place with many rivers are going to find traveling by boat or animal much more practical than traveling with something that has wheels. In that context, the wheel is not a 'better' invention or one that is necessarily an 'advance' on, for example, boating technologies. Geography is only one possible factor why one technology might not be better, even though it seems like it 'should' be. Other examples might be economic viability, available materials, available workforce, market forces etc.

When people compare societies in this way, there is often an assumption that things always move in a way we decide as 'forwards' and if things do not move forwards, some catastophe prevented the natural order of things, for example, the collapse of an empire or religious involvement. This particularly comes up within Europe after the collapse of the administrative Roman Empire. Technologies that the Romans had used frequently, such as the construction of complexly layered roads, were no longer used. The wealth, workforce, administrative organisation and societal need for such roads was no longer available. However, waterwheel construction continued unaffected, developing beyond Roman techniques and was a rich area of change in the 500-1500 CE years. To compare these societies doesn't make sense--Rome engaged in certain kinds of engineering, appropriate to its societal needs. Later engineering focused on new societal needs. Was Rome more 'advanced'? Is a Roman road 'better' if you have no need for long-distance roads of that kind?

I think one of my favourite modern examples of how technology is not linear is Concorde. If you were writing a children's book about the history of planes in 1995, you would probably put Concorde at the end, as an example of very modern plane, an improvement on previous, slower passenger jets. But we all know the story, after being launched in the 1970s, Concorde was never very viable. It fulfilled a niche that market forces didn't really need filling. As the fleet aged, it was phased out. Now, we live in a post-Concorde world, with only hints of supersonic passenger possibilities floated now and then. Have we 'regressed'?

No! Aircraft continue to be developed in numerous different ways. The technology of aircraft has moved on considerably since 1970. Note how in the passenger realm, this has focused on making planes lighter, more fuel efficient, able to use different types of fuels and larger. These planes are not a regression from Concorde, they are an alternate route of development, selected by societal pressures, needs and inventions, leaving Concorde's (the actual idea of Concorde the transport vehicle) as an era artifact in a 1995 children's book.

But there's even more to this: Concorde, like the loom, like the printing press, like the waterwheel, like the Roman road, is not an invention that is taken up or discarded whole. Packed inside Concorde is an array of ideas, many of which we have used elsewhere. Some of them we will not have used-- but we may circle back to them, rediscover them, or reinvent them without having any idea that someone had the idea before.

Technology is not linear, traveling towards some future ta-daa moment. It is full of loops, pauses, off-shoots, spurts and shifts. To say it does not 'advance' or 'progress' at all I think is a mistake because it sort of does battle with the definition of the words themselves, but it is difficult to say between societies and even between technologies that fill similar niches and fulfill similar functions (Concorde and passenger jets, batteries and grid electricity, bicycles and cars, waterwheels and windmills etc.), what is 'better', or what is 'more advanced'.

What do you mean by linear, precisely? I feel like it's a slippery sort of phrase that's hard to argue one way or the other unless you really nail it down first.