I especially prefer OSM for pedestrian route-finding. I use it on Android via Maps.me, but there are various other apps too. Google Maps seems much more oriented towards road maps and often pedestrian-only paths will be missing, at least in the UK.
What I haven’t found is a decent app for replacing the functionality of my old Garmin: showing maps and doing logging to a GPX file at the same time. Maps.me can show a track of recent movements but can’t save it.
https://osmand.net/ might be something for you.
As an update to this, it turns our that in fdroid, there is a fork of Maps.me called just Maps that adds just this functionality. The problem with osmand is the limited downloads.