i have been using mutt for more than a decade after that, until i discovered sup (supmua). for me one of mutts's big weaknesses (and that of every other commandline client) was that it could only keep one mail folder open at one time. at some point i had four instances of mutt running in parallel in multiple screen/tmux windows so that i could switch between folders without having to reopen each one.
sup fixed that by allowing me to open multiple views and keeping state while switching between them. it also replaces folders with tags and an extensive search interface with saved searches that can be treated like virtual folders.
i haven't looked back.
sup inspired notmuch, that brings the search feature to other mail clients (including neomutt) but i don't know if neomutt also keeps state between views. i am sticking with sup because of that.