Yeah I think Unity just doesn't have the technical skillset anymore to make the migration to coreclr. It keeps getting delayed and their tech leads keep dropping out.
Might I suggest https://github.com/stride3d/stride, which is already on .net 10 and doesn't have any cross-boundary overhead like Unity.
Stride has a fraction of the features as unity.
Godot is the only real open source competitor, their C# support is spotty. If I can't build to Web it's useless for game jams as no one should be downloading and running random binaries.
A real sandbox solution with actual GPU support is needed.
Imagine you have to communicate that rewrite and drop of support for bought "addons" to the people who went on that shopping spree. Who then would have to explain the "wecan"-value drop + cost of recovery of the same abilities to the shareholders and customers. The magpiesnest of bought companies tech is a tarbaby for any tech lead, the rewrite a career ender for the CEOs office.
Progress has been painfully slow, but Unity does seem to be moving forward.
Unity updates on their plans and progress:
2022 - officially announced plans to switch to CoreCLR - https://unity.com/blog/engine-platform/unity-and-net-whats-n...
2023 - Tech update - https://unity.com/blog/engine-platform/porting-unity-to-core...
Unite 2025 - CoreCLR based player scheduled for Unity 6.7 in 2026 - https://digitalproduction.com/2025/11/26/unitys-2026-roadmap...