You not only need a good quality rack, you need a decent set of matched balls and a table not beat up in the racking area. A template rack makes all those things much less of an issue. IMHO the template racks are a big shift in pool equipment for the better. They offer pretty much no drawback past small nick picking like "it moves the balls when it's hit" and "it's too good of a rack" and has major benefits, tight consistent rack all the time, less time trying to get a tight rack, non-skilled pool payers can rack as well as anyone else using them, low cost, easy portability.
I would put the template racks and the LD shafts as the biggest two improvements to the sport in the last 40 or so years. Only thing that would equal them is better plastic for the balls from the old ivory and early plastic formulas, jump cues, and the quality and weave of the cloth that Simonis did. I can't think of anything else that had as much of an impact of how the game is played. Jump cues are the only ones one would argue made the game "worse" out of all of those, even if they did make a huge shift in the game as far as overall impact they had. Personally I would not put jump cues in as an "improvement" over what we had, they made a hard skilled shot too easy. The template rack just made the rack the proper way it should be, tight all around, even though it made breaking easier with that high level of precision.