Really? You think so? I could be wrong, but that doesn't seem at all the case to me.
First, I think a lot of this is just skill. You dig around in the stuff that's publicly known, find usernames and links to old bios, and then start searching for those usernames on every social media site to see if a unique handle appears on OkCupid, PornHub, etc.
Second, on the resource side, there are tons of data brokers that have a ton of info on all of us. You don't think CNN has $50 to drop on a file filled with tracking data on a senate candidate? I think even broke local newsrooms have access to license plate reader data and leaked medical records and a ton of super personal info. I don't think they tend to use it, because a lot of them are understaffed and it's less cost-effective than just writing up local police blotters and whatever appears on Nextdoor. But I don't think it's hard to get this stuff at all.