What spiral? You just start another brand, producing extremely similar but unenshittified products. When that one takes over the market, you enshittify that one too. It doesn't matter that one brand died, because you keep making more. That's the cycle.
It’s hard for a large company to survive on something with a vastly smaller market share. You can make a living buying a portfolio from other people making it slightly worse over time and repeat, but the pipeline gets expensive and the market is fickle.
Instead the model that actually works is to buy companies, load up on debt, pay yourself from that, and then let the zombie crash and burn. Part of that process is goosing quarterly returns with deferred maintenance etc but the model depends on a sucker lending money rather than the market.