There's also been a greater focus on reproducibility: https://guix.gnu.org/en/blog/2023/the-full-source-bootstrap-...
For any readers unfamiliar with the importance of reproducible full-source boostrapping, please consider reading the paper "Reflections on Trusting Trust" by Ken Thompson [0], the creator of Unix.
[0] https://www.cs.cmu.edu/~rdriley/487/papers/Thompson_1984_Ref...