There's something to be said about code that just works out of the box. I don't see the need to maximize dependence on third-party libraries as long as the gains are purely "ergonomic". Especially when the creators have a somewhat mixed record regarding long-term commitment vs re-inventing their own wheel.

The real selling point of R imho aren't the data science tools anyway - for that we already have the amazing Python ecosystem (which also the RStudio guys have tacitly admitted with their rebranding) - but the pure statistics packages. Especially if you need something more niche, to the point that you'd use any language just to get an implementation of a specific model, you'll find yourself coming back to R more than half the time. It's simply the language of choice where most statisticians publish their code.