Totally true. I always think that eventually some kernel change may totally break how Redis works and I'll have to resort to implementing the same stuff in user

Totally true. I always think that eventually some kernel change may totally break how Redis works and I'll have to resort to implementing the same stuff in user space. A simpler parallel path is to use Redis Cluster / Sentinel and provide good safety for when persistence is disabled, and achieve data safety via redundancy in replicas. However even in such a scenario, it will be kind of handy that Redis can persist so that restarts performed with SHUTDOWN (for example for upgrades) will still retain the dataset when needed.