In every genre there are those plot devices or character achetypes that always seem to aboud. These tropes can shape the genre or shape the stereotypes that non-readers hold about the genre. This can be good and bad. Obvisouly, if the trope weren't successful it would not continue to pop up over and over again.
For us romance readers, these recurring elements (Alpha heroes, mistaken identity, fake engagements, plucky virgin heroines) are often what keep us reading. Who doesn't love to read about a brooding Alpha hero with a mysterious secret who is unable to control the strong emotions he feels for the fiesty "on the shelf" (28 y/o) spinster? We love it, but we know the genre chock full of tropes. Secret baby? Character with fatal illness that can be cured by the supernatural love interest? Unrequited love? Friends to lovers? Enemies to lovers?
Good authors know how to take these standard elements and present them in a fresh way, or can twist them about, turning it on it's head. They give us the tropes with a twist. These are the authors who make us excited to read more. It is unfortunate, though, that for every author who does this, there are coutless other who continue down the same old worn paths. The rut in the road made by all the previous authors must be pretty damn deep.