Because the hardware is available now. When somebody builds a RISC-V laptop people will start working on software for it. In any case, the GPU getting built in

Because the hardware is available now. When somebody builds a RISC-V laptop people will start working on software for it. In any case, the GPU getting built into RISC-V SoCs is a PowerVR one, there is supposed to be an open-source driver being written for it but right now the situation is no better than for the Apple M1.