Any device or software that allows people to communicate is going to be used for hook-ups. It’s etched into the machine code at the heart of the internet.
There are subs for specific areas and have been for years. Not that I’d used them, cause I don’t live in the USA. But they are nothing new and I wonder why they are only found out about by people now? Maybe because there’s no other worthwhile content there anymore?
There are subs for certain cities. Houston for example. So people who live in or near that area can meet up. They don’t have to drive across country. I guess there are probably r4r subs for many cities across the US that have lots of reddit users. But I don’t know. I only stumbled over this by chance years ago.