Its backend performance also appears to be quite bad, e.g., they banned Bing from crawling them because they couldn't handle the 0.5 QPS of load that Bing was sending their way: https://twitter.com/danluu/status/981992814824378369.

But, computer performance continues to improve and discourse will probably be usable on a cheap phone within a decade and maybe servers will also become fast enough that they'll be able to handle 0.5 QPS of load.

The bigger issue is that the design is strongly anti-user in a lot of ways, e.g.,