As someone who switched from Samsung around the time the S7 and Note 7 received criticism for battery heating issues, I can say "compelling" is a vague term because it's open to interpretation.
What compels me as "features" are: iMessaging, built in wi-fi calling in the OS, best app support, fastest processor on the market, good camera hardware and software, a clean OS, 3D Touch, no-frill software, strong standby battery life, dual speakers, water resistance.
Compared to the S7 and S7E: I won't get a good iMessage competitor, no built in wi-fi calling into the OS meaning that I have to rely on T-Mobile variants, apps are a bit behind on Android, the Snapdragon 820 is worse than the A9 processor, no 3D Touch, some Touchwiz frills, inadequate standby battery life, no dual speakers.
Is that worth going for a QHD Screen, 4GB RAM, better cameras, Samsung Pay, AMOLED tech, 5.1/5.5" screen, a beefier battery, multi-window, Samsung Touchwiz features, Micro SD Slot, VR experience, wireless charging, quick charge, Android OS, and cheaper pricing?
To me, it is not because my iPhone gives me less headaches. I don't need a spec sheet like the OP3, Google Pixel XL, or S7 Edge. Until I see otherwise, I don't think Samsung will match the experience because they don't support their products as well as Apple nor do they offer seamless warranty support. Not to mention, the bloat Touchwiz has? Such horrible waste of storage space. And why do Samsungs bog down so quick after several months?
When I went to Canada, I took my old S7 Edge and iPhone 6S Plus with me. I used my iPhone 6S Plus more because the experience is so much better for me.
Objectively speaking: yes, the S7 can do more than the iPhone, therefore it CAN be seen as the better phone.