But many users stick to it as its scoring system to prioritize emails is great at handling thousands of emails from mailing lists.
Mu4e and notmuch have excellent clients for Emacs. I slightly prefer notmuch as it has a simpler UI. Mu4e is a bit more polished, but I found its mail compose setup much less friendly than Gnus or notmuch.
One can set up notmuch as an excellent MUA centered around saved searches. I prefer such a workflow to tags or folders:
Have you ever tried mew? I heard a few good comments about it in the past but I have no idea how it compares to these clients.
Mu4e and notmuch are Gmail-like clients. Quite modern and well-maintained. Centered around searching and tagging.