Cancelling Gigaya is proof for why Unity needed to do Gigaya in the first place. It is easy to quickly build prototypes and small games in Unity. It is hard to build modern PC/console games in Unity. Every game developer who has built PC games in Unity all the way to the Steam store knows what I am talking about. Far too much game developer time gets spent searching for work arounds once a PC/console Unity game gets to a certain size.
The entire reason for Gigaya was to build a full modern PC/console game in Unity, so Unity would be forced to realize and fix some of the headaches that exist. Unity seems to have pulled another Unity here. Unity built a small demo for Gigaya and then gave up as soon as they ran into some of the headaches PC/console game developers constantly see with Unity. Giving up at this exact point is the most predictable Unity response.
There are tons of obvious show stopping bugs and limitations that disproportionately affect PC/console game developers. For example, back in 2016, I documented a bug in the scene file system that prevented 64 bit builds from accessing more than 4GB of assets. It was a 32 bit limitation in 64 bit builds. But since this bug did not affect small mobile games, it took a few years for Unity to fix the bug. I worked around the bug by breaking my game systems into my multiple scenes and then using multi scene loading. I also tried using AssetBundles as a possible workaround, but AssetBundles had its own group of show stopping bugs at the time. Here is a thread about the 4GB limit per scene bug:
The 4GB asset limit per scene was fixed in Unity 2020.1. I only bring that bug up here because it is an excellent example of why game developers targeting PC/console would like Unity to build a complete modern PC/console game using Unity.
I would love to see Unity attempt to finish Gigaya. And not just a small playable demo. Build a complete modern PC/console game. Run into the headaches as the team scales up the game. Fix those headaches. Improve the engine, editor, and tools.