That they are delivering useful capability is orthagonal to whether or not they have a moat. They have first-mover advantage, no doubt, but there's very little stopping others from catching up.
And yet they don't!
Talk is cheap.
Anthropic have just hired a Chief Product Officer (Mike Krieger - co-founder of Instagram), so you may see more layered on top of the core AI if that is what you are referring to, although they seem to have a different focus (more corporate) to OpenAI, so don't hold your breath for an Anthropic AI girlfriend.
OpenAI seem to be trying a shotgun strategy of productizing GPT any way they can, but I'm not sure that's the best long-term strategy. Maybe better to build an ecosystem - build the OS/APIs, and let 3rd party's build the applications on top of that.
And Google showcased the project astra thing, which seems like the equivalent.
Remember Duplex [1]? Which then turned out to be fake. The more recent fake Gemini demo? What an embarrassment.
LLMs also aren't correct 100% of the time, far from it.