If I was actually using Windows Mail for anything (it is linked to an Outlook.com account that I don't really use) this would be a good motivation to stop using

If I was actually using Windows Mail for anything (it is linked to an Outlook.com account that I don't really use) this would be a good motivation to stop using it, but for the vast majority of users I'm not sure they'd have a clue about how to change. In addition the range of non-browser email clients seems to have narrowed quite a bit in the past decade - what besides Thunderbird is still around?