One could compare the main branch against its state from one year ago to find out if the core product justifies this scale. I would say that, more likely than not, it isn't.

https://github.com/tailwindlabs/tailwindcss/compare/main%40%...

TIL they use Bun:

https://github.com/tailwindlabs/tailwindcss/commit/1e949af9a...