While “丧失” isn't a uniquely cultural term like 关系 (guānxi), its usage highlights a key feature of the Chinese language: precision in word choice, especially regarding formality and severity. In English, the verb “to lose” is a workhorse, used for everything from losing keys to losing a loved one to losing your mind. Chinese, however, prefers different verbs for different types of loss. “丧失” sits at the most formal and severe end of this spectrum.
“丧失” is rarely used in casual, everyday conversation. You will primarily encounter it in more formal settings.
The most common mistake for English speakers is using “丧失” too broadly, as they would use “to lose.”