No real advantage especially with a mostly idle system. But it's a good idea to keep up with the versions anyway. The upgrade processes isn't really complicate

No real advantage especially with a mostly idle system. But it's a good idea to keep up with the versions anyway. The upgrade processes isn't really complicated and if you can afford a downtime not really challenging. In my experience it's typically easier to migrate from version x to x+1, rather than waiting a long time and then migrate from x to x+5 (or similar big jumps). But regardless of the strategy for major version upgrades (10 -> 11 -> 12) you should at least keep up with the minor updates (10.1 -> 10.12)