It's not exactly true, but the incentives still align in practice. "Contact Us" Licensing has always existed as you state, but has often included the possibili

It's not exactly true, but the incentives still align in practice. "Contact Us" Licensing has always existed as you state, but has often included the possibility of royalties, and even when it doesn't it's always been at the price ranges where shipping a game was more likely than not. And in-fact, a problem with early Unreal licensing has been Epic's approach to support of "If it's not a problem in an Epic game, it's not our problem" Which has improved dramatically since changing their licensing model. And regarding Unity, yes, their ad networks are becoming more important, but that still doesn't do as good a job at aligning incentives, but more importantly, Unity has 15+ years of development in a model with unaligned incentives, which when you're talking about technical decisions, those are really important. And to be clear, I'm not arguing against the point that Epic being a game developer first is an important factor, I think it very much is, however I'm suggesting there are also other contributing factors.