If after reading the post you're still unsure about why we're going through this process, I made a video that focuses more on the reasons from the perspective of a Zig contributor, showing how the bootstrapping process helps contributors on their day to day tasks.
Thanks, the explanation about how the Zig compiler uses compile-time code execution to implement multiplatform support in the compile-to-c-backend helped me understand why WASM has better trade-offs for Zig than other bootstrapping options.
For others, the start of the video is discussing boostrapping in general, and the current compiler state, and then the discussion about "Why WASM" starts at around minute seven.
https://youtu.be/MCfD7aIl-_E