It's not just that there was a three-tier system, but I would argue that in this particular case, it was the legalization of homebrewing that was the gateway into the innovation.
Early 80's and 90's homebrewers were essentially hackers [1], doing things at very small scales, and branching far out into experimental recipes and techniques. I'm sure there was innovation in distribution and retail over the last 40 years, but definitely nowhere near the scale of the actual brewers.
Without homebrewing, you don't get the wave of 80's self/indie hackers interested in the first place. So yeah, I could believe the author was right, without the three-tier system the little amount of innovation in brewing couldn't overthrow the total amount needed to also take over distribution and retail.
Maybe the analogy would be the first touch phones, or what Tesla is doing now with EVs.
1. https://hbr.org/2016/05/the-founder-of-dogfish-head-on-flout...