[ThrowawayR2]

Seems to be the usual build vs buy dilemma: you can faff around with a less complete, less supported platform and hope it saves you money enough versus the money you spend to make it do what you want it to do to be worth it or you can license an off the shelf, batteries included platform with a lot of tooling and support that lets you focus on building your game instead.

The twist is that enterprise software is supported for many years where a game ships only once. You cannot count on shipping multiple sequels to amortize the engineering costs of going with a customized engine.