It really wouldn't. If a corporation reduced their production of for example red meat, another one would simply scale up their production, because the demand of the market would remain unchanged.
Also, there's already more than just a "small percentage" of people who have dropped red meat from their diet. All vegetarians, vegans, pescetarians, and people who eat meat but stopped eating red meat due to the environmental impact add up to several percentage points, which is absolutely measureable and impactful.
that's actually not the case, after the third gauntlet room there's one of those giant drill spikes you have to hit that falls and breaks through the floors below, letting you skip all 3 major gauntlets, only leaving the short 4th one
regarding runbacks, imo they're fun, so sure, they take time, but anything in a game takes time to do. And all but one of the runbacks are less than like 40s long, I see them as a phase 0 of boss fights, and greatly enjoy them. They also change things up so it's not just permanently fighting the boss itself the entire time. My caveat here is that the movement system being fun adds to that a lot, so in things like the 3rd person Souls games, if it's just a long sprint, it's not as interesting, whereas Silksong has one of my favorite movement systems in gaming, so I even looked forward to the runback when I died against Last Judge.