In vanilla Civilization VI and Rise and Fall, this policy helps players who've focused on Science, Production, or military bring in some extra Gold. In Gathering Storm, it also provides these players with extra Culture, helping them catch up on civic development they may have neglected and giving them extra lasting power against opponents who are trying to win a Cultural Victory.
The Third Alternative (or Third Position) is a nationalist political philosophy that emphasizes its opposition to both capitalism and communism, instead synthesizing radical ideas from both. Those following this approach favor state ownership of production and the distribution of goods and services to “the productive members of society,” peaceful segregation of ethnic and racial groups within the state, and have recently embraced radical environmentalism. Classic examples of this philosophy include Sukarno, Nehru, and Nasser.