I read in reddit, voat, and a few unmoderated sites. You never know where the link trail might end up. Tumblr, for instance, is a favorite --and not often for something you'd like to see in your history.
You could also use it to prevent defacto profiling of, say, your health-related research.
https://chrome.google.com/webstore/detail/incognito-regex-fixed-ver/okaigpjdjpcecnghfiegfopahbkcejak
BTW, I have uBlock Origin and Privacy Badger enabled for incognito.
That's a very good idea. In FF I have it destroy all history and cookies at closing; so it is basically like incognito every time I run it.
It's particularly pertinent if you have (increasingly browser-savvy) kids/grandkids visiting. And you should have it installed as a lesser watchdog even for your casual browsing machine.
Case in point, here in NC we have the on-going HB2 transsexual bathroom law which I'm following. Some of the best kick-the-politician's-ass reporting is done by the LGBT community. The sidebars of those sites lead pretty quickly into stuff like the San Fran street festivals --complete with porn-ish photos. After a while, your cookies end up looking like one of those trannies NFFC saw in Bangkok.