Street Fighter V plays very differently to Street Fighter II though. If they didn't have these changes to gameplay, Halo 5 would have been as irrelevant to the market as H2A.
You have to ask yourself what makes Halo, Halo. And while yes, I'd have liked older aiming, and no sprint, it's not realistic anymore to ignore it. So, much like Street Fighter, they kept the on map weapons, no load outs, equals starts, map control, power weapon control, respawn times and even after death cam on body. But they switched up movement options. Hell they even have a medal in H5 for grenading the power weapon to you, called Combat Evolved.
I mean again, the drops and decline of Halo 5 have less to do with the changes to gameplay itself as opposed to things like no Firefight, Spartan Ops, more maps and gametypes. I feel Warzone should have had one more mode in addition to normal and Assault as well as maybe 5-6 maps at launch. Arena definitely needs more maps, needs classic gametypes. Right now, for me, it's like okay 2 matches of warzone, that's it, a match of breakout, maybe SWAT, some BTB. I don't like doing team arena or slayer without someone else to play or coordinate with do to quitters and no mics so I've been avoiding that. If there was Firefight, something else, challenges that give a lot of points or more REQ packs, I'd have greater reason to play. Infinite Ammo and Grenade skull would've definitely made me play more Campaign missions again and again especially legendary etc.