I don't think you quite know what relative means, but that's OK it's the internet and is expected.
The problem is not the squish or the secondary stat breakpoint changes that have been introduced. The problem is that mob health pools and damage are higher than they were previously in respect to player power. I use schwarzkopf as an example, as he notes that his health has dropped by a factor of 26 times, damage by a factor of 21 times, but mob health has only decreased by a factor of 7 times. This sort of discrepancy has never happened before.
What you are referring to is the squish which brought about a readjustment of secondary stats to curb the exponential growth in power; however, this did not lead to drastically increased times to kill mobs as balancing was done around players having lower secondary stats. The more notable change was the loss of the Artifact Weapon - which lost its traits but was still incredibly powerful - and Legendaries only became disabled during BfA leveling experience after Azerite is introduced to players to reduce the feeling of loss of power; however, it did not make mobs that were previously trivial to kill within a few seconds take, potentially, minutes depending on how the class/spec.