The main benefits of Guam being a U.S. territory are:
  1. Military protection and strategic location: As a U.S. territory, Guam receives military protection from the U.S. and serves as an important strategic location for U.S. forces in the Pacific[1][4]. Guam hosts major U.S. military bases and has been a staging area for U.S. operations.
  2. Access to U.S. citizenship and travel: Residents of Guam are U.S. citizens and can travel and work freely in the U.S[1]. The Guam Organic Act of 1950 conferred U.S. citizenship on Guam residents.
  3. Use of U.S. currency and economic benefits: Guam uses the U.S. dollar as its official currency and can potentially benefit from U.S. economic resources and aid[1]. However, Guam's status also makes it vulnerable to financial crises[1].
The downsides are that Guam residents cannot vote for the U.S. president and have limited representation in Congress, despite being U.S. citizens[5]. Many Guamanians feel they are treated as second-class citizens[5].
Sources [1] ELI5: What is the benefit of being a territory (US or otherwise) rather ... https://www.reddit.com/r/explainlikeimfive/comments/j1ybat/eli5_what_is_the_benefit_of_being_a_territory_us/ [2] [PDF] by Hawaii and Alaska prior to statehood, could represent a step https://decol.guam.gov/sites/default/files/Incoperated-Territory.pdf [3] Territorial Exceptionalism and the American Welfare State https://michiganlawreview.org/journal/territorial-exceptionalism-and-the-american-welfare-state/ [4] Why Guam is American ? : r/geography - Reddit https://www.reddit.com/r/geography/comments/12x833b/why_guam_is_american/ [5] Guam: What it means to be from a US territory | Human Rights https://www.aljazeera.com/features/2018/8/24/guam-what-it-means-to-be-from-a-us-territory