It does not really matter how long it has been going since if there is more transaction being piled up day in day out anyway, it would still remain like that until it reduces. People have already given you the main cause and no one can know pretty much exactly what could be making the transaction to be that way.

Still, it is understandable like someone said, that people are trying to move their tokens and Eth into exchanges, since there is a possibility of a change in trend and they would not want to miss those peaks to sell and buy back lower which I believe explains why it could be that way.