I find it strange that omniscient (a.k.a Time-Travel Debugging) is not more common, or even the default. I assume it is due to memory cost, but it could also just be that low adoption leads to low development effort. Anyone here with experience in this topic?

That’s actually common in exploit hunting between releases of operating systems as a way of locating the changes routines from a patch Tuesday. Sadly most people I know use VMs and resource intensive snapshots to handle it