While borrowed power has always existed in wow, (tier sets, the legendary items from MoP and WoD), since Legion, borrowed power has become more influential than ever in terms of gameplay. In fact, I would go on to say that things like artifacts, leggos, azerite, etc. have been essential in terms of how classes play in their respective expansions.
On the one hand, borrowed power means that the player is always working for something. Almost everything they do will build up on their character, and there really aren't moments, at least in theory, where there is nothing to work for because of it. Moreover, some of these effects from borrowed power have been quite cool, and have had positive gameplay changes for certain specs.
On the other hand however, you could argue that these borrowed power systems often make the base specs feel a little bare. Worst case scenario, some specs don't even play properly without these systems. Moreover, some players may not like all the work that has to be put in to maintain their borrowed power. Finally, these systems mostly just exist for one expansion, so you may feel a big loss when these things go away in the following expansion.
So what do you think, do you think borrowed power is bad? Can blizz hit a middle ground with these borrowed power systems? Would you prefer if such systems were gone entirely>