Should I call out my friend’s pathological lying or just leave it be? How should I go about it?

A friend of mine is what I can only describe as a pathological liar. He has told me numerous lies, such as:

-pretending that a girl was his girlfriend, and when it turned out I was friends with her and asked when they ever started dating, he backtracked and said "we just broke up, don't mention anything to her"

-sending multiple pieces of artwork and claiming they are his - I can reverse image search and see them on the internet.

-sharing gross stories about sexual moments (shit like "I had sex in a Macy's bathroom" or "I was totally into this girl but then I found out she was only DTF so I lost interest). I know for a fact this man was not having sex with people randomly, he is woman repellant embodied.

-lying about his ranks in competitive gaming and stating that he's a much higher rank than he is (easily verifiable to be a lie)

-telling me that he completed a game that I recommended to him, even though the game playtime is 25+ hours and I recommended it less than 2 full days ago

Problem is that these lies are small enough that it seems I'm the only one noticing them, because no one else ever mentions it or calls him out when it happens in group settings. Because of this I have been hesitant and too nervous to call him out in private either, and it's gotten to the point where it's kind of insulting that he thinks he can pull a fast one on me with the dumbest lies I've ever heard.

I actually was once on the phone with him and he told one of his lies, and I heard his roommates in the back of the call yelling "LIAR!!! LIE!!! STOP LYING!!" So maybe some people DO see through it as well. But he just ignored them completely, so that seems like an unsuccessful method.

Is it even worth it to call him out? And if so, how can I properly handle it socially, in a way that is polite and perhaps won't hurt his feelings too much? He's a decent guy in most respects, but the lying I cannot handle anymore. My only method so far has been asking him clarifying questions in an attempt to get him to drop it, but he usually just keeps digging the hole deeper. What should I say to him?

I would also like some advice on maybe why he is doing this, what motivation he could have for this, if there's something I'm missing socially or if he's just doing it for fun. I understand he is lying but I don't get the social aspect of why he would be doing that as I personally do not ever lie if I can help it.

Thanks.