[ThenAsNow]

While the points you make are true, they don't address the parent's hypothesis about engines, which is true. Once you get into commercial jetliner engine sizes, the fewer the number of engines for a given thrust level, assuming equivalent internal technology, the lower your fuel burn will be. It's a matter of minimizing unavoidable per-engine losses, like bearing losses, cooling losses, endgap leaks in rotor tip regions, etc. These kinds of losses do amortize well with engine size.