I even occasionally throw one out there myself.
But why the fuck is is suddenly replacing the humble full stop?
Is there some confusion as to its purpose now it's so prolific?
People literally just finish a sentence with it. Even if it is not a statement that in any way, shape or form would induce laughter from either the writing or reading party.
These aren't people attempting sarcasm either.
It's not punctuation.
"I have an IKEA Billy bookcase, it's excellent LOL"
"I think my gerbil is dead LOL"
"Have you tried adding deionised water to your iron, op LOL"