I have email going all the way back to 2013 or so, and don’t like the idea of all that information sitting readily available for hacks, warrants, or automated scanning. I move mail older than two years into a local Thunderbird folder to limit what’s sitting online, while also letting me search for recent emails while out and about.

Aside from that, I like that I can still access emails while offline, see all my inboxes, contacts, and calendar in one place. Also, I’ve got enough “apps” that run in the browser.

Actually, sudden account closure without recourse (which Google does) is another reason to make sure I have local copies of email too.