If you still need or want the old editing experience, you don't need to switch to a fork. WordPress is keeping the old editor available as a plugin for at least the next 4 years: https://wordpress.org/plugins/classic-editor/
Anyone who made customizations to the old editor has 4+ years to figure out what to do about Gutenberg (plus they have had the 2 or so years that it has already spent in beta).
Anyone who made customizations to the old editor has 4+ years to figure out what to do about Gutenberg (plus they have had the 2 or so years that it has already spent in beta).