According to TV Tropes, one of the coolest, most addictive wiki’s on the internet,
Tropes are devices and conventions that a writer can reasonably rely on as being present in the audience members’ minds and expectations.
Tropes aren’t bad in and of themselves bad and are not inherently cliché on account of their widespread use in mainstream media.
In fact, tropes can be very useful, particularly characters tropes, which can provide a firm foundation for character development and serve as a helpful cue to readers and viewers about the sort of character journey (and hence the sort of story) they can expect.