In my opinion, it is not online arbitration that is very useful, but a professional self-regulatory organization.
Such non-profit organizations are created in various fields of professional activity. For example, in the construction industry, in the field of auditing, in the field of insurance, etc.
Online casinos can also create such a self-regulatory professional organization. Who but online casinos are experts in the field of gambling? There is a need to resolve disputes between gamblers and casinos. This suggests that there is a need to develop professional industry standards. There is also a need to enforce compliance with these standards.
This can be done by self-regulatory professional organizations.
Such an organization can also perform the functions of an arbitral tribunal.
The said organization needs to be approved by the various countries and each of their actions and activities should be as transparent as possible. Only then would it function as a proper one that could manage and be the middle man between users and the industry that they are handling. Then again, I hardly doubt it could happen, especially when it comes to gambling. Many countries have varying views about gambling, after all, and having a central organization that manages them would probably have a lot of conflicts.