[TheRealPomax]

I'm trying to understand this sentence: it seems to suggest that PHP is only popular because of Wordpress, which just... makes no sense? Wordpress uses PHP because PHP existed, and was good enough to build Wordpress on. And it's certainly not just clinging onto life, hanging around just because Wordpress is built on top of it, today?

So it's hard to understand which similarity you're asking about, but SQLite is popular because it does one thing, and does that one thing really well, and that thing also happens to be a perfect fit for complex file formats.