If you already know the area, why would you need your nav to direct you to the alternative route instead of just driving it?
Often I’ll prefer a slightly longer route over another, but if it’s much longer time wise because of bad traffic then I’ll go with my second choice. But navigation apps will almost always suggest the fastest way, even if it’s only an estimated minute faster.
Apple Maps will suggest multiple routes if they’re close in estimated time, but I’d like to weight some of them more heavily such that they might still be the preferred route even if it’s 10 minutes slower since it’s simply more pleasant safer.
My navigation apps keep up with those better than I can.