If the level of detail in printed topo maps satisfies you, then Outdooractive Pro seems to cover that, at least for some countries. It claims to have Swisstopo, Kompass, DAV/ÖAV, as well as a range of "digitalized official topo maps" which include DTK, ÖK, IGN, OS, Harvey, and some for Slovenia and Italy which I cannot really judge.
I haven't tried it myself, but you can set up a free trial account. (I'm not affiliated in any way with them.)
The only next level I can think of, besides satellite imagery (but you have that already on Google maps), are specialized cadastral maps for forestly like this one, but they are hard to find and too specialized to exist across countries and in publicated form.