why do people put the extra X in there? indolence?

My best guess is it’s become a sort of linguistic meme, poking fun at incels who’d ramble on about things like “looks-maxxing”.

Or maybe it’s a combo of that and “min-maxing” from gaming communities. The extra X makes it more maximum. LOL

Taxing, faxing, relaxing…

"…Shootin’ b-ball…

When a couple a’ guys, who were up to no good…

Started making trouble in the neighborhood…"

–Prince William Smith of Bel Air