The challenge is that I haven't seen anything better really.
Lately the innovation comes mainly from deeper integration with tools. Standalone AI editors are mainly popular with people who use relatively simple editors (like VS Code). VS Code has a few party tricks but for me swapping out Intellij for something else on a typical Kotlin project is a complete non starter. Not going to happen. I'd gain AI, but I'd loose everything else that I use all the time. That would be a real productivity killer. I want to keep all the smart tooling I already have and have used for years.
There are a few extensions for intellij but they are pretty much all variations of a sidebar with a chat and autocomplete. Autocomplete competes with normal autocomplete, which I use all the time. And the clippy style "it looks like you are writing a letter" style completions just aren't that useful too me at all. They are just noise and break my flow. And they drown out the completions I use and need all the time. And sidebars just take up space and copying code from there back to your editor is a bit awkward as UX
Lately I've been using chat gpt. It started out pretty dumb but these days I can option+shift+1 in a chat and have it look over my shoulder at my current editor. "how do I do that?" translates into a full context with my current editing window, cursor & selected text, etc. all in the context. Before I was copy pasting everything and the kitchen sync to chat gpt, now it just tells me what I need to do. The next step up from this is that it starts driving the tools itself. They already have a beta for this. This deeper integration is what is needed.
A big challenge is that most of these tools are driven to minimize cost and context size. Tokens cost money. So chat GPT only looks at my active editor and not at the 15 other files I have open. It could. But it doesn't. It's also unaware of my project structure, or the fact that most of my projects are kotlin multiplatform and can't use JVM dependencies. So, in that sense, every chat still is a bit ground hog day. It's promise to "remember" stuff when you ask it too is super flaky. It forgets most things it's supposed to remember pretty quickly.
These are solvable problems of course. But it's useful to me for debugging, analyzing, completing functions, etc.