Steve Ballmer said something about Apple a decade ago that has followed the former Microsoft boss around like a bad smell ever since.

At the time, smartphones were a growing, but tiny, part of the wider mobile phone industry. Microsoft was an early pioneer, its mobile software second only to the all-conquering Nokia.

So when asked about the iPhone, an expensive new device from a company best known for portable music players, Ballmer was justifiably dismissive.

"There's no chance that the iPhone is going to get any significant market share," he said.

"I'd prefer to have our software in 60 per cent or 70 per cent or 80 per cent [of phones], than I would to have 2 per cent or 3 per cent, which is what Apple might get."

Ballmer was, of course, wrong. People were, as it turns out, willing to spend hundreds of dollars on a phone. Those who weren't opted for devices running Google's Android software rather than Microsoft's.

The company that had dominated computer software for decades became an irrelevance on mobile phones, and realised it too late. Ballmer no longer runs Microsoft, and he now tweets from an iPhone.

The ascent of the smartphone, and the varying fortunes of the major companies orbiting the industry, has defined the last decade in tech.

Apple and Google were the winners. Microsoft lost, and most of the large tech companies now live in fear of "doing a Microsoft".

The question that the company got wrong in 2007 - What happens after the desktop PC? - now haunts those who replaced it.

What happens to Apple after the smartphone? What happens to Google if AI assistants replace internet search? What happens to Facebook if we start hanging out in virtual reality instead of online?

Nobody really knows what new technology is going to take off next. It could be the internet of things, or AI speakers like the Amazon Echo, or virtual reality, or augmented reality.

Tech companies are doing everything hoping that something will stick. As a result, they are all starting to look the same.

And what will those categories look like? Should AI speakers be small and affordable, or expensive and high quality? Will augmented reality come through hi-tech glasses, or merely our smartphone cameras? What about driverless cars?

Predicting the future isn't easy. But these are the questions we expect the world's most innovative companies to grapple with.

And, at the moment, they are not coming up with any answers. Instead, tech companies are doing everything hoping that something will stick. As a result, they are all starting to look the same.

The first high-profile AI assistant, Apple's Siri, was launched six years ago. So far, they have not quite had the impact that Star Trek imagined. But despite this, every big player - Google, Amazon, Samsung, Facebook - now has one.

In 2014, Amazon became the first to put its Alexa assistant in a speaker, rather than a smartphone. Smart speakers remain a small market in the grand scheme of things, but every company now makes one.

It goes on: chat apps, music streaming, internet TV devices, language translation, image recognition, virtual reality, self-driving vehicles: everybody seems to be doing everything.

This isn't exactly surprising. Today's tech companies have enough cash at their disposal to throw resources at everything. And nobody wants to repeat the mistakes of Microsoft. It is easier to spend a few million to establish a foothold in a market than to ignore it.

They are playing defence, not offence: strategies have moved from "let's do something new", to "let's make sure that nobody else is doing something we're not".

But it also speaks to a lack of vision. The reason no single piece of technology from a major tech company has had an impact approaching what the smartphone did could be because none of them have the full-throated backing of their makers.

When Steve Jobs launched the iPhone, it became the future of Apple. Making it a success became the company's mission.

Compare it to the HomePod smart speaker Apple will put on sale later this year. It comes to a market where there are already multiple smart speakers that will largely do the same thing. The company's future in no way hinges on the success or failure of the HomePod.

When everybody has their fingers in every pie, people just get messy fingers. Consumers get confused about ever-moving goalposts and, rather than embracing new products, they avoid them. Ideas are copied by competitors, which makes coming up with them less lucrative.

But as well as being bad for innovation, it is also the wrong lesson to draw from Microsoft. After realising his mistake, Ballmer spent his final years in charge of Microsoft attempting to catch up with Apple and Google in smartphones, culminating in the doomed $7 billion acquisition of Nokia's mobile unit.

It didn't work. Windows Phone continued to suffer; under Microsoft's current chief Satya Nadella, what remained of the Nokia business has been brutally gutted and smartphone development has stopped.

Instead, the company has been refocused on cloud computing and productivity software. As a result, its lost decade has come to an end. Shares have doubled since Nadella was appointed in 2014.

Microsoft's fortunes have been revived not by the company trying to do everything, but by it playing to its strengths.

As other tech companies all start to resemble one another, perhaps they should do the same.

Telegraph, London