Tinder hit on to a psychological hack that allowed normal people to use it. It's something to do with plausible deniability. Setting up a real dating profile signals that you know what you want but implies that you are lonely/unhappy. Tinder gives that vibe of "I'm just swiping, look at all these losers, I'm just having fun". So normies went on it too.
At that point you're down to real users who are jerks, the solution to which is the block button and a message sorting algorithm that takes into account how many times it's been used against someone.
Now tell me all the reasons you won't do it.
As to why I don't do it, maybe I will -- but I wouldn't object if someone beat me to it. Because it still requires some combination of time and money, the amount of which can be feasible without being zero, and it's quite likely that of all the people in the world, someone who isn't me is in a better position to pull it off before I do.
This isn't going to be bring in anywhere near the amount of money you're thinking it will.
Is such a thing even possible in today's world where attention spans are measured in seconds thanks to a decade of social media and endless pursuit of "engagement"?
Dating apps were easier to bootstrap back in the day before the whole market was swallowed up.
The only way to have a fighting chance is to start in a single metropolis (eg New York), and try to get everyone to coordinate trying at once. Since the demographics of people complaining about dating sites online is a bit small (and selects for the kinds of clients you don't want), you've got to advertise more broadly, eg with ads on Youtube or in the metro. That gets expensive.
People need some way to find out about it, but not everything has to be corporate. Wikipedia has this page which ranks near the top for search queries like "list of online dating sites":
https://en.wikipedia.org/wiki/Comparison_of_online_dating_se...
You're an online dating service, so you get added to pages like that where people end up when they're looking to choose an online dating service. And then your site compares well against the other ones that are screwing everyone -- look how few of the heterosexual dating apps have free messaging. So people sign up and give it a try.
You make sure your site is listed in places like that where people go to find dating sites, and people find it. And the more people find it, the more useful it gets, because that is how network effects work. At which point people start recommending it and you get even more users.
Something highly local might work in a big enough city like Paris/London/NYC.
Edit: Match and others definitely did get patents, so I may be confusing them, but I guess no matter who, you'd get sued by someone.
I don't know how prevalent this phenomenon is, but that's at least 0.9 on the Mad Max scale.
(As a demi/gay man, online dating is incredibly alien to me.)
Some of them don't even bother with a bio, it's just a few photos and a link.
And then there's the bots which just start a generic conversation and recommend some Clash of Clans clone or something.
But as mentioned, you realize that in the first 5 mins of interaction.