Around 40% of my portfolio is in stable, dividend-yielding stocks. I invested in more speculative stocks when I was younger, but I wasn't able to outperform a general index fund. (Regardless of what you read online, hardly anybody is able to do this consistently).
You won't get rich quick, but good dividend stocks will, over time, match or exceed the returns from the TSX, with less volatility. (If you're using a metric that looks at risk-adjusted returns, such as the Sharpe ratio, dividend stocks usually perform very well).
I like the fact these companies have to pay a certain amount each quarter. (Obviously that can be reduced, but that usually hurts the stock price, so management doesn't do it unless they have no other choice). It forces management to be disciplined with the shareholders' money. Being able to read and understand financial statements can help you understand if the dividend payout is sustainable.
All of my dividends are set to DRIP. Companies used to offer discounts for reinvested dividends, sometimes substantial, but that's less common these days. Still, I never touch the cash, and keep getting more shares each quarter.
For stocks held outside of sheltered accounts (RRSP, TFSA etc), dividends are taxed at a lower rate than regular income. The difference depends on which province you're in, and what your marginal rate is, but for me, the difference is around 16%. (A stock yielding a 5.0% dividend yields slightly more, after tax, than a bond yielding 6.5%). (NOTE - this paragraph is based on Canadian tax rules, I can't comment on how this works in other countries).
As I said, I don't have all of my money in dividend stocks, but it's been a good way to build wealth over time. It's not glamorous or exciting, and you won't get rich overnight, but it's highly improbable that you'll lose money (adjusted for inflation) long-term. My goal is to retire once my (after-tax) dividend income covers my annual spending.