Webpack 5 was released 10th Oct 2020. See announcement: https://webpack.js.org/blog/2020-10-10-webpack-5-release/
It's too early to switch to it, but we should consider that in 2-3 months from now, so at the beginning of 2021.
The most important from development side would be first 3 features they present in the announcement:
Improve build performance with Persistent Caching.
Improve Long Term Caching with better algorithms and defaults.
Improve bundle size with better Tree Shaking and Code Generation.