Is there actually any legit way to see what someone's public Instagram profile looks like to a stranger without logging into my own account or asking someone else to check for me? I'm not trying to see private accounts, just want to view public ones without being logged in. Seems harder than it should be.

I've encountered this too. I don't want to log in to my account every time, especially if it's not my computer. For such cases, there's Blinkviewer. Just copy the login or profile link, paste it into the field, and that's it. You see all public posts as if you were a random visitor. No authorizations, no traces. It's convenient if you need to see what the page looks like after changes, or just watch someone's content without a subscription. There are no paid features, everything is free.