I also use the Komoot app, but it requires a data connection to do routing. Sometimes it picks a crazy route and I will manually force it to include a point to pass through to get it back to reality.

I also have Maps.Me on my phone, I download the maps for my area and can use it later off line. The bike routing option did not seem to pick very good routes last time I tried it, that was last year. Maybe it is better now. I often thought that the car driving routing was better for bike touring if I was not near any USA interstate roads.

I mostly use the routing option on my Garmin GPS (Model 64) using the tour cycling option and minimize ascent option. But when touring I will often compare all three of the above to see which option looks best.

And occasionally I pick a route off of a paper map instead. The routing apps and my GPS routing system often appear to prefer a road that is a state road over a county road and a county road over a local road. But sometimes the local road is perfectly fine for biking and if it is shorter distance I might use that instead.