Buddhism is pragmatic. It is a religion of methods , not of Truth. The methods are ways of approaching enlightenment.
Truth and methods | Vividness
The other vehicles, such as the Mahayana, address the weakness of sentient beings by deliberately employing the dualistic concepts of right and wrong. In these other vehicles you will see safety measures, rules, clear directions, signposts, benchmarks, indicators. They are safe; they provide clear direction.
Jamyang Khyentse • The Guru Drinks Bourbon?
Christianity does not have yanas. It does have sects: Catholic, Baptist, Mennonite. So when Westerners first started trying to understand Buddhism, they assumed Buddhist yanas were sects. Mostly this confusion has persisted, and even many scholars still get this wrong.