There are some projects that aim to improve the merging model of Git, such as pijul[1]. Git uses "three-way merge" and it is fairly well-known that the repository state you end up with for non-fast-forward merges (merges that need merge commits) is not necessarily well-understood in all cases. Pijul uses a more efficient algorithm that has well-understood merge characteristics, and is designed around patches not repository states (which means that conceptually patches are the core -- rather than in Git where patches appear to be core but are actually all generated on-the-fly).

It should be noted that Git was not unique in its design. There were many source-control systems that had the same model that pre-dated Git, it's just that Git was fast and significantly easier to use than the other tools. The previous tools would not have been usable for developing Linux, and so Git was obviously necessary.

[1]: https://pijul.org/