ChatGPT obviously has the marketing advantage, but it also seems to have the advantage of not being tightly bound to any particular platform.

Microsoft's copilot is tightly integrated with my Windows devices, but not with my Android phone. Google's Gemini is tightly integrated with my Android phone, but not with my Windows laptop.

ChatGPT isn't tightly integrated with either, so I get broadly the same experience no matter where I use it. Weirdly this feels like an advantage despite actually making it overall more difficult to use.