Tinder doesn't control it, but Match as a whole definitely does in a whole lot of markets.
And yes, it'd be a massive problem if Tinder controlled it in that it'd put an unaccountable company in control of whether or not people get access. And one with a history of refusing to engage people who feel wronged.
If Match expands that to its other properties then it becomes a problem even if Tinder alone doesn't dominate.
I don't think that's true. Tinder doesn't control the dating app market, nor would it be a problem, per se, if they did.