36 spoke wheels built by a qualified wheel builder using double butted spokes should not be breaking as you described. I roll on 32 spoke fronts and 36 spoke rears at 135-140kg on a regular basis for years without issue. My guess is either the builder(s) are hacks, or the spokes are junk. You didn’t mention the specifics, but where and/or how a spoke fails can provide a clue as to the source of the problem.
Stick with name brand double butted spokes and talented builders. For the ultimate wheel build you might want to consider triple butted spokes, but I’ve never needed to go that far myself even at the extreme weights I’ve described.
Before I started building my own, I called around to several different shops and asked “other than yourself, who is the best wheel builder around?” A couple of names were mentioned repeatedly and sure enough they delivered. You might wanna try something like this.
-Kedosto