The thing that kills a common lead acid is deep discharge. Just one or two deep discharges can ruin the charge storage capacity.
Another thing that ruins a battery is overcharge.
I have dozens of lead-acid batteries. I have three tractors, one car trailer with two large batteries that are solar powered, one trailer that requires a charger, a 14 Mustang, a 92 Mustang, an 89 Mustang, and an F250HD diesel with two batteries.
In all of these batteries, there is no correlation between extended sitting and battery failure. Some go six months sitting, the one trailer well over two years. When I have a bad battery, without exception, it is because I left a key on or a light on.
My truck is a good example. I've probably put three or four sets of batteries in it. The problem is I leave something on without it running. If it kills the batteries one time, they are noticeably weaker in ampere-hour capacity. Two or three times and they are shot. It isn't keeping the batteries topped off that helps, it is letting them go deep discharge that hurts. My 14 sits for a month or more, my 89 all winter, my one trailer for years. My truck is used almost daily and it has by far the largest issue, and the problem is always me. OTOH I've had some lead acids just sitting on the floor in the pole barn for several years and they are still good.
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89 LX. 363, single turbo S482 FMW, Super Vic EFI, Fox Lake Stage III heads, solid roller, glide. Holley HP EFI. (combo varies)