It'll keep continuing until you get one FPS and no audio without paying for premium.
If your product stays current/modern with paid new features and the free portion is left to rot, it is enshitification. Enshitification is not a specific behavior or feature set. It is a product lifecycle of first tailoring your product to the customers to increase market share, then tailoring to advertisers to increase revenue and solidify market dominance, then tailoring to investors and squeezing your customers and advertisers for every last penny and cutting costs wherever possible as your product becomes worse and worse for the original customers. It's the shifting of target audience and abandonment of the previous that is a natural byproduct of infinite growth.
Enshitification is not simply "product becomes worse because x". Though, I'd argue that diverting resources to premium features while allowing the non-premium features to become obsolete is a tangable worsening of a product.