Tracking is recommended as a measure of protection against false claims of non-delivery and claims of unauthorized credit card use.
How reliant you are on tracking will depend on the type of merchandise you sell, its value, and the likelihood of buyer fraud.
Tracking generally isn't of much use to buyers unless they live in areas where porch piracy is a problem and they need a sense of when their item will arrive, but most of the time buyers obsessively track their items unnecessarily, not realizing that it doesn't make their items arrive any faster or even guarantee their arrival. (Been there, done that.) It's been way oversold as a buyer "benefit" when it's the seller that benefits most from tracking.
However, at the very least, given that the bar has been raised by other e-tailers when it comes to shipping speed and trackability I'd suggest you not offer surface mail to your non-US international buyers and not entertain any requests to use it.