This logic seems mad. If people only need SLMs then hyperscalers can also centrally host higher-efficiency models, and still gain efficiencies of scale and convenience over hosting locally.
There may be a great deal of advantage to be able to run a small language model on something I have in my hand, disconnected.
Although mainframes have their use, the pendulum of centralized to distributed has gone back and forth and there are benefits to be gleaned from either model, sometimes at the same time.