I needed it many times (and it was often unavailable). When I wanted to continue with previous conversation or refer back to something GPT said.
I even experienced it indirectly when I asked someone on reddit about a prompt they have used to make something (generate a pretty good video script) and OP said that they would gladly share it, but unfortunately the history was down.
I don't use GPT to get information in a search-engine manner.
I found it very helpful when writing a blog post series about teaching GPT to translate ROT13-encoded text--instead of documenting each prompt as I went, I could just get into a flow state with the model and try a bunch of things, going back later to pick the moments that gave me an insight.