I believe they have three options
1. Say it’s meant to be like an iGPU, and work on supporting dGPUs to complement it.
2. Say that they want to compete with dGPUs/Apple and risk losing their mobile crown. Which is what Apple did in exchange for one design across all products.
3. Say they want to have a split product portfolio. A more desktop focused GPU for Snapdragon X with a more mobile centric one for 8xx