that assumption is really "theoretical" and personal. The visa conditions don't tell you can stay for an arbitrarily long time. As others have pointed out, H1B is explicitly temporary and does not in itself lead to a permanent residency path. The US is not like others countries, say UK, where staying for 10 years in some visas or 5 years in a work visa lead you to PR. What they've transformed the H1B in is sort of "unwarranted"