"Make frequent small queries and let a smart cache do the right thing every time" sounds like "make a perpetual motion machine". It just sounds like a fundamentally difficult problem with unavoidable tradeoffs. I admit I don't know the details of Apollo, but I find it hard to believe that a caching layer magically solves everything without introducing very gnarly bugs. A cache layer makes concurrent editing harder, for one.
The Apollo cache doesn't magically solve everything, certainly not concurrency. It's a state store like redux/pinia/mobx, with automatic normalization plus other goodies like being able to query/mutate the store locally with gql if you want. Doing N+1 cache-only queries is also no big deal, though I don't do so myself. They probably should have called it a state store and not a cache, but whatevs...
