I use and pay for Wanderlog. Idk how their business is doing, but I love it as a user. They use an embedded Google Maps viewer for locations, so there is no problem for coverage.
If they become popular they'll have to move to OSM, Google's steep charging for their Maps API at high usage that has brought companies to their knees is well known [1].
For now, they do use Google Maps and I’m happy with it. If they stop and it’s no longer as useful to me, maybe I’ll stop using it.
But I use it as a glorified notes app to keep track of flights, reservations, rental cars, confirmation numbers, etc, in one place, not for trip planning.