Why would they even bother coming to Earth?
Unless life only arises once every few billion galaxies, or rarely even in alternate dimensional timeline changes, if life is extremely rare in the universe, then the search and effort would be worth it.
Our non organic resources on Earth are not rare in the universe. They all exist in high volumes among the outer asteroid belts and other planets.
Organics can be grown easier in a lab or a farm.
Unless....it is a holy mission.
Divinity.
Perhaps regarding the search for the creator?
Diving deeper into the workings of the universe.
The 2 blue crystal tablets (combined to form a cube) capping the pyramid, waiting for the 25,000 year 5 degree Earth tilt to complete its gate cycle back and forth, turning the Northern African desert into a bountiful, lush paradise, and allow another large group of humans to migrate and pass northwards.

Or....maybe we just owe them space taxes.....