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.
Most platforms don't support customers to claim coins or tokens sent to a wrong blockchain. They can do it but security wise for their platform treasury, they are not too opened for customer support in these cases. Some platforms can support customers, but with support fee and it's not cheap but very expensive. If your lost fund is not big, let it go because it doesn't worth to pay expensive support fee for your fund reclaim.
However, support or not, it's policy of each platform and if they state in ToS that they don't support it, then they state it again in Customer Support conversation with you, it's done and your case can be considered as a Closed Case.
There are warnings in Deposit and Withdrawal Procedure on both platforms, so if you as a user, ignored all these important warnings, it's your big responsibility to be so careless.