So many reasons. JS has a small standard library, a history of competing standards for things like asynchrony and modules, there are tons of different implementations against tons of different specs, running in tons of different environments (whose constraints and opportunities are also changing all the time), it tends to be the first language to receive an SDK for many services, packages tend to be almost-excessively granular because optimizing for size can be so important on certain platforms (tree-shaking and minification works, but takes time), there are many add-on languages like JSX and TS, there are tons of bundlers and transpilers which each have their own quirks... and also due to its unique position as the lingua franca of client-side web, it tends to be the primary battleground for researchers, tech firms, VC, FOSS, malicious users, and everything else.

To stay alive in an ecosystem like that, any project must become a "ship of theseus" kind of deal.

You may be interested in yarn's "zero-installs" option: https://yarnpkg.com/features/zero-installs