esbuild is and has always been governed strongly by Evan Wallace. I can't vouch for whether or not the Evans (both Wallace and You) talked to each other about it, but I'm almost 100% certain Wallaces' vision for the esbuild project is different than what rolldown is ultimately trying to achieve.
In some respects, rolldown is also the next generation of Rollup (potentially) and is a direct answer to rspack[0], which is a webpack compatible rust based toolchain from ByteDance
In some respects, rolldown is also the next generation of Rollup (potentially) and is a direct answer to rspack[0], which is a webpack compatible rust based toolchain from ByteDance
[0]: https://www.rspack.dev/