The forum is a really great tool, contains a lot of functionality and allows rich discussions between users.
Compared to the forum, Zendesk looks like a dinosaur that nobody wants to use anymore. Zendesk has a “desirable” interface, it lacks a lot of functionality and it gets raided by spam bots.
Furthermore, bringing all ideas together on a single platform could avoid creating confusion and sidelining certain interesting ideas.
Currently, the forum is presented as a tool for creators, which means it could be presented differently to welcome feature requests that don’t necessarily concern creation. (as mentioned here: https://forum.rec.net/t/category-for-in-game-qol-features/2904)