Yep, I'm pretty sure for the majority of users it's for watching porn or logging in with a different account to something, rather than any expectation of privacy at the other end
I also use it on the rare occasions where I need to log in on someone else's computer. This way, I know all my logins will be ended when I close the browser.
Haha same. When using the printer in my apartment's "tenant office", I can at least know that a sandboxed incognito window will offer some protection.
Assuming someone hasn't installed a key logger or OS tracker :(