What's the point investing in AT&T or KO over high-yield Dividend stocks?

Hey everyone. I'm not new to investing and have been doing pretty well, but one thing I've never quite been able to figure out is why people recommend investing in companies like AT&T or KO or other consistent dividend stocks instead of higher yield dividend stocks like GAB or USA.

The only thing I can think of is consistency. T and KO are unlikely to go anywhere. But the amount you get in return is very low comparatively.

For instance, I have 91 shares of GAB offering $13.66 a quarter in dividends and the market value is only $508. But I also have 26 shares of T offering $15.82 a quarter, but the market value/cost on that right now is $1404.

I get that dividends aren't usually what people go for when they're younger, but I try to be diverse just in case, and this is one thing I can't quite figure out why one type tends to be recommended over another.