The SL2 is almost exactly that (a little out of your suggested price range with a kit lens, but it's a better camera than most people need for Instagram and the like), if a DSLR is even the right choice for that demographic. Every manufacturer has something in that ~$500-$700 range that is similarly competent; I only mention the Canon SL2 because it is the most effective when it comes to being "smart" (the new autofocus system in Canon cameras is by far the best in the market; it's frighteningly good, and much faster than a human operator could be). But, 1080p (or 4k) video, good automatic settings, etc. are all pretty standard across the board from every manufacturer. It's hard to find a camera from a good manufacturer that doesn't work great.
But, there are also cameras in your suggested price range that aren't DSLRs that fit the bill, probably better than a DSLR for the casual camera user. A lot of the smart tech in DSLR cameras has trickled down into point and shoot cameras, including good autofocus, white balance, etc. Lens technology has moved more slowly, but the digital part of cameras has been advancing extremely rapidly.
But, there are also cameras in your suggested price range that aren't DSLRs that fit the bill, probably better than a DSLR for the casual camera user. A lot of the smart tech in DSLR cameras has trickled down into point and shoot cameras, including good autofocus, white balance, etc. Lens technology has moved more slowly, but the digital part of cameras has been advancing extremely rapidly.