Migrate from Vuex to Pinia for store management?

Vue3 is recommending Pinia over Vuex for store management. Pinia is basically a defacto implementation of what had been planned for Vuex 5. And there is quite some differences to note such as mutations no longer being a thing.

Thankfully, there is a migration guide. But like with migrating to Vue 3, I doubt this will be 100% easy.

Note: We will likely have to wait until we really refactor our stores.