Interstate is battery marketer, not a battery manufacturer. They hire others to make their batteries, and if Johnson controls made an interstate sold in Maine, it is no guarantee Johnson controls made the interstate sold in Washington state.
The worst battery kept fully charged, will outlast the best battery chronically undercharged. Reports of longevity without knowing how well the battery was treated, are a highly unreliable yardstick.
Also even if manufacturing quality varies greatly amongst starting batteries, it also varies year to year, and a 5 year old battery with Sticker X applied that performed awesome, is likely not made by the same manufacturer anymore.
If you want a battery to last, fully charge it often and do not rely on the alternator/ vehicular charging system to top it up and keep it topped up. If one is really anal about battery life, protect it from engine heat too.