There are plenty of both transformer and non-LLM "edge" models that aren't free and open - think anything that ships in consumer electronics. Vendors usually want this IP protected.

And, the same GPUs are run in datacenter, where there's a big insider risk that vendors want to mitigate with encrypted models (if you're Anthropic and you want AWS to host your models, you don't want 5000 or even 500 or even 50 AWS employees with access to your highly valuable/desirable model weights).