This is true for most games, the benchmarks on various sites which usually say Max settings aren't actually max settings, i.e. they are leaving some settings off which have huge impact on performance. Like TXAA, hairworks physics etc and if you turn on those settings your frames does take a big hit.
True those settings doesn't provide much eye candy for the amount of impact they have on FPS but in my books if i say MAX settings then i REALLY mean max settings.
You can find many benchmarks on various sites where you will find gtx 1070 achieving over 100 fps in many games at 1080p resolution at supposedly 'max' settings and if you get the card yourself and do turn on everything to absolute max you will find a huge fps difference which might make you think if somethings wrong with your card but its not.
I recently upgraded from GTX 970 SLI to single GTX 1080 and i am happy for now. My biggest reason for upgrade was 8gb vram and poor or no SLI scaling in many games. The games where there was little to no SLI scaling my FPS has doubled (Rise of the tomb Raider, JC3, Arkham Knight) but the games which did have scaling my fps has still improved an average of 10%.
So everyone has his own reasons for upgrade, if OP want's an upgrade then i still think 1070 is still the best bet for him if he doesn't intend to go above 1080p.