In this case that’s not accurate. Im a UX developer by trade, and have spent years developing interfaces to manage large data sets for CRM systems, Reporting Systems, and other large data interaction platforms. This problem is easily remedied by tools.
So many companies develop around small data sets/limited scope usage and completely degrade when it comes to managing larger load. While this is on very active forums, it can easily be solved by the solution(s) I recommended. It would be much more manageable to have a stop tracking function per topic on the “unread” page than having to click in and out of each topic, or to try to read every topic so I can use the dismiss button. The uglier way would be to have a checkmark by each topic and allow that to be affected by the dismiss button instead of all of the entries in the list.
Its been implemented in any number of other interfaces and applications and has drastically increased usability there.
Discourse is an amazing forum software, but there are a lot of limits when dealing with large amounts of data for a user. Ive been perfectly fine navigating smaller forums, but when you get to the ones with a large user base, all of this extra steps and pitfalls make it much more complicated to handle effectively.
Take for example the overwatch forums at blizzard. They have tens of millions of people as customers and their forums just fly. Some thought should be put towards being able to navigate these forums lest they become unusable (which there are a number of features that are approaching that on larger sites)