There are already open source LLMs with comparable parameter counts (Facebook's OPT-175B, BLOOM), but you'll need ~10x A100 GPUs to run them (which would cost ~$100K+).

I suspect a big part of why stable diffusion managed to consume so much mindshare is that it can run on ordinary consumer hardware. On that point, I would be excited about an open-source RETRO (https://arxiv.org/pdf/2112.04426.pdf) model with comparable performance to GPT-3 that could run on consumer hardware with an NVMe SSD.