> I genuinely don't see the reason why non-cryptographic random number generators exist outside of niche applications.

Because for well over 99.99% of developers, cryptography is a “niche application”.

I’ve never written crypto code I’ve deployed anywhere. If I need crypto, I use the highest level crypto library I can find that people I trust who _do_ know about crypto recommend.

The only time I ever recall non cryptographic random() functions to have surprised or affected me was way back when I discovered if you forgot to seed the random on an AppleII the games I wrote in Basic all started out with the same “random” choices.