Outlook was always the outlier for me that keeps me in MS - I moved to it over 20 years ago from Pegasus Mail (anyone remember that?!). As I have to deal with a lot of mail (and I own a mail-hosting business), I've tried all sorts of apps and sites and never found anything as remotely good as Outlook for getting through a boat-load of mail quickly.
2010-2019 was great, the latest versions from O365 are just awful, buggy messes that have numerous graphical glitches (on my Intel / nVidia laptop and AMD / AMD desktop and my work laptop), frequent crashes and hangs. Genuinely the last thing that keeps me as a MS user for home and it's falling apart. The web version is also very poor for working with large amounts of mail, I'm genuinely not sure what I'll use once 2019 is no longer supported.