Seems our experiences are vastly different. Back when I used KMail I had no real issues. Never lost emails and it worked with all my account (I didn’t use Gmail at the time).
I haven’t used it in a long while though, so my experiences are old. It doesn’t sound like it has improved since. :(
Android 14 has the option to present itself (the phone) to a computer as a USB webcam. Very handy and does not require any special software on the PC.