Earlier quoted context omitted.
How do you know this? Is there actual reporting on what percentage of honey in supermarkets is adulterated, rather than just anecdotal reports that at least some is?
Honey supply chains are opaque and global, plus the incentives to cheat are clearly there and it's hard to definitively prove a batch was not adulterated. I'd say it's fair to be suspicious. That said, this old article seems to think its not as common a problem as you would expect: https://www.npr.org/sections/thesalt/2011/11/25/142659547/re...
Anecdotal but everything in that NPR article rings true to me. American consumers are used to the bear shaped bottles with purified honey that’s barely distinguishable from sugar syrup and could easily be adulterated but the raw honey I usually buy is so obviously honey from the taste and texture that I have a hard time believing any of it is adulterated. If honey producers were really that good at artificially replicating flavor profiles, they’d be far ahead of the rest of the food science industry.