The power of 老土 (lǎotǔ) comes directly from the cultural context of China's rapid modernization over the past few decades. A huge cultural gap emerged between the fast-developing, trend-setting cities and the more traditional, slower-paced countryside.
Anything associated with the “earth” (土) or the countryside was seen as the opposite of modern, stylish, and international. Therefore, 土 (tǔ) became a powerful slang adjective for anything considered unsophisticated or uncool. Adding 老 (lǎo) emphasizes that this lack of sophistication is a thing of the past and has not caught up to the present.
Comparison to Western Concepts: A good comparison is the American concept of a “hick” or “country bumpkin.” These terms similarly stereotype rural people as being simple and out of touch with urban culture. However, 老土 is broader and can be applied to anything—not just a person, but also a piece of clothing, a song, an idea, or a phone. While in the West, “vintage” or “retro” can be extremely cool, 老土 is almost never a compliment. The positive Chinese equivalent for “cool vintage” would be 复古 (fùgǔ).
老土 is a very common, informal, and colloquial term used among friends, family, and on social media.
Connotation: It's almost always negative or teasing. You might use it to gently mock a friend's taste in music or fashion. It can also be used in a self-deprecating way to show humility or humor about one's own lack of trendiness.
Formality: Highly informal. You would not use 老土 to describe your boss's strategy in a business meeting (you might use the more neutral 过时 (guòshí) instead).
Common Topics: It's frequently used when discussing:
Fashion: Clothes, hairstyles, accessories.
Media: Music, movies, TV shows.
Technology: Using an old phone or outdated software.
Ideas: Holding onto old-fashioned beliefs or ways of thinking.