With the growing emergence of technology and our busy routine, everyone is busy on their own; people are considering their lives so busy! Are we becoming less happy in this modern era of technology?
Very good question. Though you don't directly correlate happiness and technology in your question, the implication is clear.
Your question at least hints at the age old debate between people who see virtue in Nature (championed by Jean-Jacques Rousseau (1712—1778)) and those who see virtue instead in technology.
Before discussing predictions, we might try to answer your question directly. We might ask if depression is increasing.
In fact, Depression IS increasing, according to many reports. Still, that isn't really a definitive answer. Depression wasn't really closely studied or measured 1,000 years ago, and psychology can be a little flaky.
As others have noted, technology has given us some really cool things, including advances in health care. But there always seems to be a tradeoff. Modern transportation is a major contributor to climate change, for example.
I would argue that what distinguishes the opening years of the 21st century is the proliferation and worsening of global issues, including overpopulation, climate change, genetically modified food, the Internet (with a focus on propaganda, spying and manipulation) and militarization.
The problems created by early automobiles, refrigerators and tin cans were largely manageable, even if they weren't properly managed. But we've leaped into a domain where we can scarcely understand our problems, let along manage them.
Fear of the unknown is one of the greatest phobias, and I think many people have a deep, instinctive fear that something is horribly wrong, not just with our government or society but the planet itself.
Yet another factor in the U.S. and at least some other countries that is at least loosely linked with technology is the economy. Many people are forced to hold down two or more meaningless jobs in order to make ends meet. Both spouses often work.
There are still more factors. The world is increasingly urbanized, and big cities are clearly more stressful (in general) than less populated rural areas. People are more mobile, putting strains on relationships.
Depression can also be caused by chemicals or health problems.
In WiFi cafes here in Seattle, I seldom hear people discuss politics. But when they do, someone will often comment on some of the issues I mentioned above with great concern. Then they'll suddenly apologize for bringing everyone down and change the subject to entertainment, video games, whatever. People know something is wrong, and that something is so big and hard to understand, they're afraid to even talk about it.
I suspect that happiness is pretty much what you get when you have good relationships with other people, including any people having power or authority over you. To the extent that people isolate themselves with technology, I would say that "Yes, modern technology makes us unhappy."
But I would not say that this is a purely up-to-date modern thing; after all, in Charles Dickens' "A Christmas Carol" (1843), wasn't Ebenezer Scrooge's fault isolation-due-to-focus-on-things (specifically, his business)?
Likewise, Inspector Javert, the villain in Victor Hugo's "Les Miserables" (1862) lived a life "of privations, isolation, self-denial, and chastity—never any amusement". Javert, like us, gave his free attention to the written word: "In his leisure moments... although he hated books, he would read."
Still, these two works of literature were produced after the steam engine. I wonder if such depictions of human unhappiness, surrounded by media, have older counterparts!
Technology enables us to be wealthier (which correlates with happiness, at least up to a point) while being less busy. This is less evident in, say, the US compared to Nordic countries, due to social differences. Technology brings greater security and better health care. (I personally rely on devices to help me see, hear, walk, and sleep, and medicines for a lot more things. I'm happy.)
I'd expect technology to bring more happiness, and indeed it does appear to in many cases.