It won’t last. It just takes awhile for consumers to figure out that your product is now shit.
Most people aren’t visiting every day to notice the price increases or the quality decreases. And the first or second time it’s often written off as just an outlier.
Of course there’s variance per customer, but it takes a couple years before you really earn the shitty reputation of something like Dominos circa 2014. In the meantime, line looks like this before it drops. And by that time you’re CEO of a different company.