Used by people on the net who think adding ness to lol makes it funnier. They are fools. There are also such things as Lolish and Lolness which are similar in their stupidity.
Most people who use it say they made it up.
Fools.

A buzz word being used to refer to creators and influencers forming or encouraging unhealthy relationships with their fans. Usually used in the context of young audiences feeling they have a relationship with the influencer due to the huge amount of the influencer’s content they consume. The influencer in question, however, is unaware of the fan’s existence other than the general knowledge of having fans. Common examples include Dream and his stans. These relationships are exacerbated by the influencers confirming they have more than a creator-to-viewer relationship.

The word is circulating due to various YouTube essays about the phenomenon using the word, and therefore people who enjoy complaining about influencers repeating what they heard in the video in any comments section they can find.

Lolness is the word lol
which means "laugh out loud"
it is describing lol as a ness

the word lol (laugh out loud) wit ness added on the end of it for special effect made up by me an used all around the country now **im 2 cool**