I imagine data security and what the government would know is putting some off. It is part of the reason the national ID (My Number) faltered.
Off the top of my head, and I'm sure there are more, people use: tinder, bumble, Pairs, Zwei, Zekushi, and probably more. Pairs and Zwei, at least, are geared toward long-term and marriage. Pairs had a very bad UX and, of course, a cost. I did meet some people on there, but nothing lasted (one nearly did, but I wasn't doing another LTR with a barely-functional alcoholic that otherwise was a great match).
I 100% agree everywhere it's practical. Still, people are going to have to get to train stations somehow. Multi-modal transit could somewhat cover that, but some people would still practically have to drive. Convincing those people to only drive to the nearest station and not all the way to their destination is another challenge to solve.