Mutt's downfall is it's designed around a single account. Most people have at least a personal and work email account, if not more. People also access their email through IMAP these days. Mutt has many config hacks to try and make it load multiple IMAP accounts, but a single failure to auth or connect will leave mutt completely frozen.

I have to use mutt to read and pull kernel patches, but I hate it. I would love a modern tui email client to rise from the ashes, but I doubt that will ever happen.