For those who have issues with batteries lasting more than 3-4 years, I've got a couple of questions:
1. Is this consistent, meaning battery after battery fails within this time frame?
2. Which battery? Do you always buy the cheapest, middle of the road, or the most expensive AGM battery you can find?
3. What's your typical engine-off behavior? Do you or your S.O. listen to the radio after you get to your destination and turn the engine off, leave the lights on while you read for a bit, or have any other frequent occasions where you're eating into your battery's reserve capacity?
4. Do you drive short-trips often, or have a lot of start-stop cycles with minimal highway driving?
These questions are for the OP, as well as any one else who wants to contribute.