A tangentially related tool you can use to look at a repo over time is Git of Theseus[1]. It shows things like "what percentage of the code in this repo survives 6 months.
[1]https://erikbern.com/2016/12/05/the-half-life-of-code.html
[1]https://erikbern.com/2016/12/05/the-half-life-of-code.html