Specific to build tools, a number of projects are VC-funded. Rome raised millions of dollars in VC money (https://rome.tools/blog/announcing-rome-tools-inc/). This offering is now funded by Vercel.

The same problem plays out in the JS engine space (Deno raised $21M and Bun raised $7M) and in the framework space (e.g. Remix raised $3M). As long as there's money to be made and investors to fund projects, there won't be consolidation.