why non rooted android does not support sdcard formatted with ext4? Prone to data loss, fat32 or exFat are the only options right?
I just lost many files on a sdcard.
Formatted on linux desktop, to ext4, android will not reconize the sdcard, despite it could.  

my question is: why this non-sense?

lollipop here :(

is our only option for quality, to root the smartphone?
yes , not make any sense , the better I could get until now is mount ext4 , with adb root 

Mounting a ext4 formatted sdcard on Android Marshmallow

more info here: https://android.stackexchange.com/a/204616/119381