Yes. Well.

The idea that developer iteration speed is actually an indicator of project-completion-at-scale speed is really only true at a trivial scale; you know, when you only have developers. Maybe a handful of them. ..and like, one does-everything artist.

When you have multiple different teams including non developers working on actually building a significant game, crafting levels, assets, etc. the iteration speed of your handful of devs is really really a drop in the ocean.

There are a lot of very powerful tools in unreal for teams, and they have consistently invested in tooling (eg. File per actor) and real life production needs (eg. LED stage support) with their customers.

Unity has invested in different areas, with a lot of effort, and bluntly, nothing to show for it.

We couldn't even get Unreal to build as an embeddable library for a mobile app nor could we get it to build into anything that would run in a web browser despite more than a week of effort.

We had Unity working for both use cases in under a day.

This really has nothing to do with Unity. Flappy Bird could have been built on any platform and you would still have a million clones of it. Because it takes a day to make it. It's just as easy to clone that game in Unreal Engine, fwiw.

Unity didn't create the concept of the quickly built game, nor is Unity responsible for society incentivizing this type of game dev. If anything, the new runtime fees will disincentivize this type of game, so maybe that's a good thing?