Indeed they do. See Royal & Ancient Sitcoms Club - Rules of Situation Comedies, Rule 2 Paragraph 3. And Decisions on the Rules of Situation Comedies, Decision 2-1/3.
You should watch The Chinese Restaurant or The Parking Garage episodes of Seinfeld, superb examples of how the best comedy is often the most simple, revolving around one plot strand and one location. No switching of narratives, just great scripts and great acting.