Fun Fact: It's not necessary, it's merely a convenience for people who don't want to pump a lot of missiles or Ice Beam.
What Samus Returns REALLY needs is Select to cycle between Beam/Missiles, Ice Beam/Super Missile and Grapple Beam/Power Bomb, as Select for WHATEVER REASON... Is just a secondary Start. And this is not an issue exclusive to Metroid Samus Returns
You have to be the first person who feels the same way I do on the weapon select. The select button was perfect for being able to one button spam bosses with missiles. The hold shoulder button down method introduced by Fusion is IMO cumbersome, especially in handheld play where hand space is at a premium. And that got itself a hack in Super Metroid because people are crazy.
The melee counter is not necessary per se, but enemies they expect you to use it against have tons more HP than they otherwise would have, and I’m just talking about the mooks. Pads out the game unnecessarily.