This will degrade the battery and is likely the cause of the issue. Even the small load when the car sits unused is enough to cause irreparable damage. It's not enough to prevent the battery from starting the car when needed, but enough to impact the ISG (Idle Stop and Go) function.
There is battery technology designed for steady drain, but it's not suitable for starting a vehicle in all conditions.
I'm not saying you should do anything differently, it's a minor design flaw. I wouldn't expect to get more than 2-3 years from OEM batteries anyway. If the ISG (Idle Stop and Go) matters to you, then you will need to keep getting it replaced by the dealer.