The problem statement was unity projects are hard to maintain due to accumulation of tech debt. The answer is to give dev engine source access... I failed to see the connection here.
> As impressive as UE5 is, I don't think the technology has to do with its appeal as much as the long-term user experience.
I agree there's not a ton of explanation & support for this point. The post does jump to a very specific topic, whether the source is open / takes PRs. For sure there's a lot more that goes into this question. The post explicitly says it leaves others to deal with a lot of the pain of the back-half of Unity development, so it's not even like there's a ton of winning moves UE has to play: they just have to not self-inflict grevious wounds.
It is, however- unsaid in the article but clear- incredibly much easier to keep yourself in a respectable, easy to use shape when you are open source. The post talks about a specific bug, but just things like improving the build toolchain or adding support for some new developer tool: developers will happily improve their quality of life in a product, if you let them.