Why do others have these highly specialised research topics and I don't?
Professors usually love to find PhD students in search of topics, since they tend to have ideas that they hope someone will work on.  Even students who come with a defined idea often find advisors nudging them in a different direction than what they really wanted to do.

Talk to some professors that you think would be good people to work with as your PhD advisor, and see what thoughts they have on this.