I don't work for a nation state, but I work for a large financial that requires adversarial testing and it's absolutely increased the ability to operate and attack these environments. The floor is definitely easier to reach at a minimum. Vulns and 0days are far easier to exploit, time to exploitation from the release of vulns is nearing zero, largely aided by LLM reverse engineering -- why wouldn't this apply to nation state level adversaries?

Peak of skill and capability, perhaps not, for now. But the ability to automate and discover relevant weaknesses at a greatly increased rate definitely counts as increasing the threat nation states can present.