[bermanoid]

This looks like an actual log-log plot, but of new cases vs existing cases. Not a super useful view except to point out that yes, growth rate tends to be proportional to infection count (pure exponential growth) until something majorly changes.

A linear plot would tell exactly the same story, just be compressed too far towards the origin to be very readable.

[dredmorbius]

Yes, I realised that and edited my comment, apparently before you'd completed yours.

The view is useful in that it makes departure from the exponential growth trend blindingly clear. A bit fiddly trying to work out timelines however.