I’m not sure why the developers wanted to focus end game builds around sets. From the get go they must have seen that it limited the number of viable builds because there are only so many sets that can be reasonably designed. However, did they intend to release more sets but the idea got cut short with the cancellation of the 2nd expansion?
I think they looked at D2 and didn’t know where set items belonged and instead made the wrong decision to pretty much make them end game gear. In my opinion, the best place for sets are what they are trying to do with them now. Make some of the farming builds more enjoyable and interesting, such as increasing death breaths drops, increasing key drops and the WD chicken build.
They seem to go half way now about undoing the dmg with the legacy of dreams gem, but I think it’s too little too late. The system is just too broke now unfortunately and to fix it, would require overhauling all the gear.
But the idea to go with sets and its pitfalls can be seen a mile away; very disappointed a big company with talented developers did not see it coming or if they did, they decided to ignore it.