Lithium batteries will also leak and cause the same type of damage but to a lesser degree.
Fortunately, it takes them much longer period of time to leak ... but they do leak.
Sooner or later, somebody will neglect the machine and forget to change batteries.
How long do they last? Roughly 10 years, maybe less depending on brand of memory installed.
In theory, they'll last a huge amount of time with some memories but the Lithium will discharge due to internal leakage long before that. Equipment at work - we got as long as 15-20 years (5101 memories) out of lithium coin batteries but that is pushing beyond the safety period. We have had a few that age come back and they were still holding up after that much time ... but the batteries were leaking.
Although I don't have any NVRAMs in my machines and don't sell them either - I am a big fan of them. Really, there just aren't any down sides to them other than you may need to install new memory sockets.
I can see where batteries would be kept, though -- such as Wms games that kind of use the real time clock. For those, I would go to Lithiums.