– For years now, Silicon Valley has been searching in frustration for the next big breakthrough.

Innovative businesses that launched a decade ago, such as Uber and Airbnb, are finally making money or heading toward public offerings — but only after years of bruising fights with regulators and costly operational challenges.

At the same time, the dominance of Facebook, Google, Apple, and Amazon, has made it harder for new startups to burst on the scene. And the impact of powerful and much touted emerging tech, such as artificial intelligence and cryptocurrencies, has been more incremental than explosive.

Benedict Evans, an analyst at the venture-capital firm Andreessen Horowitz, said that despite these challenges, society is in the midst of a major wave of innovation, and more is coming.

In his annual slide deck — a document that many use to read the tea leaves in Silicon Valley — Evans walked the line between a tech cheerleader and a realist.

He pointed out that while tech companies have been successful at putting smartphones in everyone's pocket and connecting people via social media, they have not been as good at persuading people to shop or conduct transactions on these platforms. Less than 5 percent of consumer spending is conducted online — let alone through smart refrigerators, microwaves and other appliances. "It means we're only at the beginning of that penetration," he said. "We're at the end of the beginning, not at the end."

But other experts have said that these persistently low numbers may be because of limitations in the way physical experiences that can be digitized. These e-commerce analysts doubt all commerce will move online or onto smartphones because many consumers simply prefer to shop in person.

In another part of his presentation, Evans noted that well-known technology companies that launched in the late 1990s and early 2000s, such as Google, Facebook, Yelp or Zillow, have focused on indexing massive amounts of information and presenting it to people in more efficient ways.

Evans said he still believes that the next phase of innovation will be in blockchain, cryptocurrencies and AI. But like the internet in 2003, he said, it's hard to see all the possible applications and ways that these tools will be used.

Blockchain-based apps will be able to overcome the dominance of technology giants by enabling businesses to grow without relying on the major platforms for distribution, he said, echoing a wish among many venture capitalists that something will come along to break the current cycle.

Others have called that wishful thinking.