Why was Israel exiled to allow the land to rest? Two reasons...
1) Many sins defile the land itself. Immoral behavior doesn't just harm the immoral person.
2) God gave laws about how to treat the land, but those laws were ignored.

If you abuse what God has given you, you should not be surprised when He takes it away.

https://www.americantorah.com/....2016/05/24/bhar-5768