While United's MileagePlus members experienced major devaluations in the value of their miles, especially during the pandemics, United MileagePlus is still one of the most easy types of airline miles to earn. It's easy to earn United miles thanks to a number of United credit card, as well as a few transferable point partners. You can also redeem miles on United's extensive network of international and domestic routes and over two dozen Star Alliance partner airlines.