That's pretty much all I use it for. To keep my porn browsing off of my history.
Not to hide it from anyone, I don't live with my mother anymore and I don't think my SO would care. More so that when I google something, I don't get porn auto complete entries in my everyday browsing.
I'm fully aware that my traffic is able to be monitored by my ISP (at least to the extent that there's a connection that exists. HTTPS is still not capable of being easily decrypted), and my DNS is resolving the address for the porn sites, and that Google (or whatever search engine) is logging that the search happened.... Or that the sites see my connection, from my IP, and know what I watched.
My only objective is that they can't link that to my normal browsing or accounts.
You know all those "share on"... Twitter/Facebook/whatever links? When they load, from Facebook, it asks the referer URL, and checks the browser for any cookies that might associate that browsing to a person for ad customization. Incognito isolates that information, so while Facebook/X(Twitter)/whoever may know that someone went to that URL, they have no cookie data to link it to a person uniquely, so they have information that the site was visited, but no idea who visited the site since any session cookies I have for those services are in my non-incognito browser.