Universal Why are Apple Mail Notifications still so Broken?

[Sheepish-Lord]

I've almost made it out of the Google ecosystem (maps, gmail, drive, etc) but one thing I can't leave is Gmail due to what seems like one of the easiest things to fix and that's the badge notification system. No matter what I do Apple's Mail does not sync up across ANY Apple device so if you check your email on say your iPhone it will still show up as unread on another device until you open the app. Maybe it's my OCD or the feeling that I've missed an email but it's annoying to do a decent amount of email work from my Mac only to go on my phone at the end of the day greeted with an inaccurate number of unread emails on my Mail icon.

It's been like this as long as I can remember which is years and at one point I owned a device from each of Apple's current lineup all ato once so I know it's not just me. Can anyone elaborate on why the badge system is broken?

 

[Fatus_Asticus]

I have an iPhone and a mac book air. I use gmail forwarded to iCloud mail.

I just checked mail on my iPhone and left one unread one read. Pulled up my MacBook Air which was locked and the mail app was closed and it’s showing the same thing. Mine is updating properly.

As I delete them on my phone my Mac updates within a second.