Allow relationships on multiple columns

RE: Allow relationships on multiple columns

Why can't power BI have the same capability as SQL for joining tables, i.e. be able to do left / right / full joins using multiple columns as relationships?It seems like Microsoft have restricted the join capability to make it simple for the users, however what happens instead is that people need to do complicated work arounds to achieve what they need to do - e.g. by making a concatenated column to join multiple fields together in two tables.