This article is partially written from a personal perspective.
As someone who interacts with a lot of people that aren’t savvy regarding Sony’s version of Smash known as PlayStation All-Stars Battle Royale, I frequently see comments resembling “stage hazards should have a toggle”. It’s interesting because Sakurai addressed this a long time ago, and yet it feels like everyone somehow skipped over the one interview where he explicitly said that it would be like PSASBR if there were such a toggle. The idea of a toggle comes up frequently when competitive balance is discussed, and sometimes on more touchy subjects such as Ridley(which is particularly ironic since PSASBR’s selection of stage hazards didn’t include bosses the way Smash 3DS/U did).
Ignoring the fact that the basic design of Pyrosphere being similar to a stage in a 3DS-only game is incomparable to borrowing a mechanic from a competing company’s game, that one line in the interview holds a bit more significance than you may think. At least, when you look at it more objectively.
For the uninformed, a defining feature of PSASBR’s stage selection was the ability to disable that stage’s particular hazards while keeping the layout for characters to fight on, with background events still happening in a harmless way to the fighters, thus not making the stage feel bland. This feature made several of the otherwise chaotic stages legal for competitive play as the main offenders to their viability were disabled. For instance, Hades, one of the more commonly seen competitive stages, fast forwards the stage progression and makes the titular god a simple animated backdrop, turning the stage into a pseudo-Battlefield, which it already becomes when the stage progresses with hazards enabled.
This works for PSASBR because every stage was designed to be played on whether stage hazards were enabled or not without significantly altering the geometry of the stage in question (and because the game’s KO system is not tied to ring-outs, which incidentally can’t happen most of the time). Toggled or not toggled, you’ll still get a relatively similar experience with the stage in question, just tailored for whether a more serious or casual battle is wanted. Now what does this have to do with Smash? More than you think, actually.
Players of Smash 4 will surely know of the Omega versions of stages available, which remove all hazards and confine the match to a singular platform akin to Final Destination. It’s the same idea in concept albeit executed in a different fashion that is more familiar to the vast majority of Smash players, and sets it apart from PSASBR. With the current stage selection in Smash 4, this idea is much more consistent than a simple hazard toggle. Take stages such as Orbital Gate Assault, Kalos Pokemon League and Flat Zone X, for instance. Implementing a hazard toggle would require a complete overhaul for the stages to make them non-hostile while keeping its basic gimmick of the fighters being directly involved, which is both more time consuming than simply making a Final Destination clone and potentially detrimental in regards to how creative and varied these stages can be. Moreover, all of Smash’s hazards loop until the match ends, whereas those found in PSASBR do not.
As a result, Smash’s design choices don’t lend themselves well to a hazard toggle option in its most basic form; disabling the hazards of a stage, due to a variety of factors. Quite honestly, you really don’t need it; the Omega versions of stages do this just as well and with a more unified result that is much easier to do in practice.