Side thread from "Investment returns are real!"
Except getting a dividend literally is getting a piece of the profit. That's where 99% of qualified dividends come from. Most companies have a dividend rate that is a percentage of earnings that will be paid out in dividends. So you can see that the bolded statements are demonstrably false.
But you aren't getting anything. You get $4 in dividend per their example but share price is -$4.
You get $0, which is effectively less than $0 because you must pay tax on the dividend.
If you own a stock and you get a $10 dividend but the share price drops by $20, have you made any money? (please don't say yes)
If a company's paying out $4 in dividends a quarter, then their stock price isn't going to be $0. It should be somewhere in the $200-$300 range plus or minus health of the company, the rest of the market, forecasts, etc. etc.
In a perfect world, the price would dip $4 before the dividend, but go right back up once it's paid out.
If the share price drops by $20 after paying out the dividend, it's because something else is going on with the company or the market, or investors are just in a mood that day. If the company is making $10/share earnings and paying $10/share in dividends, then the stock price will track inflation -over the long run- and -all else being equal- (which it never is).