[isignal]

The transaction log maintained from time 0 would be equivalent but too expensive to store compared to the tables.

[10000truths]

If you relax your constraint to "retain logs for the past N days", you can accumulate the logs from T=0 to T=(today - N) into tables and still benefit from having snapshots from that cutoff onwards.

[inopinatus]

On the contrary, I’ve known plenty of sites that keep their logs.

Often written to tape, for obvious reasons.