A lot of magi are pursuing mystery goals which brings some danger, too.
In my short gaming experience I didn't see much magical botches and no chance entering twilight. Nobody learns from vis because the covenant has many books.
The latest editions favour learning from tractatus too much. Vast number of tractatus is a reasonable conclusion by raw. Learning from vis is exceptionally expensive compared to its efficiency. However learning from vis could be an obvious source of warping.
So very limited or no tractatus would lead to a situation very old magi would have lower arts. Thus a magus should choose between the long life and the power.
I opened a thread about the Hermetic society https://forum.atlas-games.com/t/hermetic-society/3565/1