It's very much a meaningful metric when the entire point of TFA is caching the commits graph. This is only an issue when you actually have lots of commits, and even more so a very branchy graph.
>It's not a meaningful metric when discussing whether to use sqlite as storage for git instead of files in the .git
There are 2 different conversations happening.
You seemed to be responding to ggp (rakoo) "sqlite db vs files".
However masklinn was responding to gp (Aissen) question of "Fossil vs Git" performance and a charitable reading would be comparing the Fossil algorithms (also affected by combination with underlying SQLite db engine algorithm) for commit searches, graph traversal, etc. In that case, the high number of commits and total repository size to stress test Fossil/Git would be very relevant.