Switch Editor has been developped in 2008 by NetDream, restarted in 2012 by Anything Digital. Anything Digital discontinued switch editor support. Say "Hi" to Switch Editor 2.
Switch Editor 2 helps connected user to switch their default editor in Joomla administration, a list of installed editor being displayed on the bottom (Joomla 3) or on the top (Joomla 4) of your admin page.
Switch Editor 2 is Joomla 3.10 and Joomla 4.0 compatible.
Important: if you are working with Switch Editor 1 (from Anything Digital), before going to Joomla 4, upload Switch Editor 2 in your Joomla 3.10 admin.
Read more https://extensions.joomla.org/browse/new/extension/edition/editors/switch-editor-2