Office UI Fabric as web components
Office UI Fabric is an awesome library, which contains a lot of components and UI elements. It's a great library to build UI experiences for SharePoint and Office 365.
The downside is, that the most feature-rich version of the library built with React. If you want to use this library, you should use React without much options. There is Office UI Fabric JS out there, however it's not actively supported and developed as React one. Also it's difficult to reuse it in other frameworks. Office UI Fabric is must-have library in almost any SharePoint Framework solution.
The idea is to make Office UI Fabric also framework-agnostic. This can be done with web-components (https://www.webcomponents.org/). web-components are built with a few W3C specifications. Most specifications are supported by modern browsers, some of them require polyfills. There are some web components libraries available today. Stenciljs (https://stenciljs.com/) looks really solid among them. It has very intuitive syntax similar to React. Good example of a library, built with Stencil is Ionic 4 by Google.
Magnus Danielson commented
These components are working with AureliaJs. I have also exposed them as WebComponents. The WebComponents are still under test though https://au-office-ui.azurewebsites.net/
100%. Have to stick to React for no reason. Even unable to use web components as react versions used have issue using custom element s