People sometimes mix up microfrontend with "running multiple frameworks". Its not the same. Actually, the main difference between microfrontends and microservices is that microfrontends should be written with an application shell and many (development) boundaries in place - otherwise the UX will be terrible and hard to get consistent.

Disclaimer: I am one of the people behind Piral (https://piral.io) which is a microfrontend solution based on React.