Also, “destroy your aerobic system” means that the upper limit of Zone 2 will get slower. Taken to extremes, the upper limit heart rate of Zone 2 will get lower.
We see the results of that all the time with new clients. Two years ago, I started working with someone who had an AnT HR (top of Z3) of 180. His AeT HR (top of Z2) was only 130. 180 / 130 = 1.38. A 38% gap is… not good.
In contrast, my fittest athletes have gaps of less than ~5%: 190 / 180.