The problem you are referring to has to do with tax avoidance, meaning planning to ensure that some income is sent to places with low or no taxation. That refers to what I was talking about earlier. In English we call it base erosion and profit shifting.
Is a multilateral agreement the only response to that? I don't think so. I think this problem has many facets and must have many solutions. We can think about national laws and tax treaties. One thing can certainly be done when it comes to tax treaties, which is to protect the integrity to ensure that third country residents do not have access to the treaty benefits. For example, the treaty with Hong Kong reflects this reality because it includes provisions that ensure that the benefits are available only to residents of the territories that signed the agreement.
That is part of the solution. The solution is not limited to tax treaties, be they multilateral or bilateral. There are also issues relating to national legislation that come into play here.