The rest of the apps I find myself using don't use those same UI/UX patterns/designs, and I don't think it matters that much: Photoshop, Terminal, Telegram, Bear, Fantastical... the list goes on. The applications that keep me coming back are the ones that are smooth and don't interrupt my train of thought (most everything here), or have some big use case (Photoshop) that keeps me coming back.
I'll also point out one more time that Telegram is what people bring up every time this discussion rolls around, so they're clearly doing something right and people must not think it looks _that_ out of place.
Hell, I'd argue that the consistency of UI/UX on Apple products matters more for the initial purchase and wow-factor than it does once a user has settled into their environment. Every application does not need to function and look exactly the same.
To be honest, this all feels like moving the goalposts, and is why I usually refrain from getting into these discussions.
Yes, but I don't feel that a message app really needs to do this to the extent that Telegram does–they've managed to make their app look out of place on macOS.