If you ask me, it’s still possible to recover the funds because Roobet has access to the address where the ETH sent. However, Roobet might be unwilling to assist due to various reasons or considerations for not handling those funds. One reason they might avoid interfering is the potential risk of exploitation, which could lead to hacking or disruptions in their system.
It can be recovered or credited to their account if Roobet allows the method he used to deposit ETH on that network/token. For now, all they can do is wait for that to happen.
There's still a chance to recover that if they support and say something about people could recover those funds sent in wrong chain. But if they have clear rules towards this and say that they are not entertaining this kind of issue then I guess there's nothing to do with that issue since in first place the affected person cannot blame Roobet for what happen since he is the one who commit a mistake for sending his funds on a wrong chain.
Maybe in future they might support hose things and this is I think the only thing he could do so that he can possibly recover those missing funds.