That's true, and those options are also awful options we used in the 90's and promptly abandoned once better options became available, though they wouldn't make that much difference here. The alternatives are all brittle and limited in different ways.
Well sort of. Server Sent Events is basically "official long polling" and it works very well. Way simpler than websockets in many cases. Websockets is obviously better here though.
The point isn't that the way the data is sent from the server matters much, but that using javascript to handle the retrieval is beneficial. The first Javascript enabled chats still relied on the same methods of retrieval for a long time, but still significantly improved usability.