I find myself using the web UI because it's much faster than MacOS Mail, which often gets a bit stuck when downloading new emails via IMAP. I'd prefer to use a native app, but it happened without me thinking - I just ended up going for the fastest option unconsciously.
Try Thunderbird. It's easy to set up IMAP to gmail, and it's very quick. Keep what you want on the server (or download and delete) and just never look at the web client again.