Its a gen z trend. My nephews do the same. We are old.
It’s older than that - lots of my boomer bosses did it to seem cool over email in the late 90s.
I viscerally remember starting my day with my inbox saying “cum c me”… I know what you’re trying to do, bro, but damn.
We are young and old all at the same time.
We are not old, there is a reason the generation is said (in stats and polls) to be less professional than prior generations when entering the workforce