My guess is that they realize the opportunity created by Mozilla’s sudden change in privacy terms.
The closest extant option is something like GNOME Web (also based on WebKit like Orion) but the lack of extension support and poor performance makes it a non-starter.
As someone who already pays for Kagi search, Orion will definitely be on my radar. I'll gladly volunteer $5/mo if I can just copy-paste my extensions unchanged and keep browsing.