PHP's Composer package manager has this same problem. Basic Drupal updates used to be a total pain in the ass - any attempt at a Git merge would most likely cor

PHP's Composer package manager has this same problem. Basic Drupal updates used to be a total pain in the ass - any attempt at a Git merge would most likely corrupt Composer state as the default merge drivers don't have a clue how to generate valid JSON. There's a custom Git merge driver for composer.json and composer.lock files. It can't generically merge all JSON but it's good enough to make merging upstream updates on a composer-managed project at least sort of tenable. This is entirely a tooling and time problem: it would be possible for Unity to ship with a Git merge plugin for their file formats, and add merge-conflict resolution to their editor, which would enable using Git with Unity. They're an ECS, which means all their objects and components of those objects should (and I stress, SHOULD) have unique identifiers that they can use for resolving merges. However, I imagine that isn't terribly easy to write and they probably have better uses of their time since everyone likes using Perforce anyway.