Have you noticed how it's odd that most of the songs by famous singers talk about love or heartbreak?

Yeah, it is an easy and inoffensive thing to write about.
That is why I prefer political punk rock.
There are exceptions, though.

And most books have drama and protagonists and antagonists.

Art and music and literature almost always comes from conflict – it is the interaction between people (often corrosive) that provokes emotional responses – and that gives the singer or author or poet something to write about.

There is nothing new in your observation. Conflict is what makes the world go around.

Since this question has been placed (badly) in ‘General’ I can’t do more than answer the OP’s ‘serious’ question: Yes, I have noticed, but I don’t suppose it’s that odd.

Oh, I guess I can place the odd remark or two, but I’m sure it’ll all be modded off.

It’s because love makes the world go ‘round. (But sex helps a lot, too!)

Average people without a zeal for music tend to like unoffensive and stale themes like love and relationships and shit. There is no exploration into anything that would make them feel and especially appear abnormal. If it’s on the radio it must be good right? Some 20 year old teeny bopper with a canned sound track and auto tuned vocals sells just like shitty, burnt, overpriced Starbucks coffee. People who buy into that can’t be bothered to understand this this this or this, hope I’m not being to harsh.

ARE_you_kidding_me

It’s all subjective really. I listened to a few of the songs you gave links to, and I thought they were horrible.

It’s an acquired taste and not for everyone.

Not odd, but completely expected