Yes, of course. But ChatGPT/Copilot is more flexible, for the same reasons it's "better" than just googling (e.g. maybe you find the solution in Java but HackerRank wants it in Python, and it's trivial to ask ChatGPT for the translation. And this is just an example).

For coding problems this is essentially a more flexible search engine, one with which you can interact better to tweak the result.

If you can simply take the challenge prompt, paste it on ChatGPT, and have an answer in seconds, doesn't this more or less make the kinds of challenges often employed in HackerRank obsolete?

My experience with leetcode at least is, you can just access the forum of the given task to look at solutions (and explanations) by other people. So for anything other than challenging yourself, it is already obsolete without additional tools.

I see how ChatGPT might be a more flexible search engine, I just don't think it is a fundamentally new mode of cheating that hasn't been possible before.

The 'real challenge' with the two computer setup is having to retype the whole task anyways ;)