Rollup is great for node packages. It can keep import/export statements (ESM/ES Modules) in place, which help bundlers like webpack only include code that is actually used in the bundle (tree shaking). I use it to bundle all my libraries and shared components.
I would recommend Rollup to anyone who just needs to get their project to work. Try to avoid this on big complex projects as at some point in the future you might run into some blocks ( most likely due to the unavailability of a plugin you need ). The setup is extremely easy and quick to get started. Even righting custom plugins is pretty easy but this may take you out of track when working on some projects. It is also pretty easy to integrate it with some CI/CD pipeline of your choice.
I had a short experience with rollup and it's a legit module bundler, with support for tree shaking / dead code elimination. While not as popular as Parcel or Webpack, it does have a growing community and very responsive maintainers. Would recommend it if you need a bundler for an npm package/module. If Rollup is good enough for React, it's good enough for you: https://github.com/facebook/react/pull/9327
Apart from Webpack & Parcel, my choice for building npm packages for distribution is Rollup. TypeScript plugin is a good addition to the config you are writing. I have run into issues with Rollup and babel with lack of some plugins support. Its comparatively faster as compared to webpack and the configurability of paths is good as compared to using TSC for bundling.
Rollup is perfect for bundling component libraries or packages otherwise intended for consumption by other projects. Module bundling in multiple formats (ES, UMD, CommonJS), tree shaking, plus a whole host of plugins. Used it in several simple projects and it was quite fast.
Before Rollup, Webpack was used for everything I created. The difference is that Rollup requires far less configuration than webpack and just feels like a lot less to need to understand to get the value out of it. I mainly use rollup to create libraries and is especially easy to create a library which supports esmodules as well as ship with types.
Very performat and easy to setup. Ideal choice for bundling packages. Though if you'll need something really customizable webpack can probably go further.