It's easy to read this as another shitty "millennial are ruining X" article that piles anecdotes on top of popular stereotypes, though it is maybe worth noting that marriage rates really are declining pretty quickly and consistently [0].
If the whole "apocalypse" thing seems alarmist, consider that Japan's birth/death ratio has been <1 for a while, and is now a matter of national concern.[0]
Of course, that's only a real problem if our immigration policies continue deteriorating.
Japan's birth/death rate is fairly bad, but at least their fertility rate is increasing again since 2005 after steady decline. Given the current path they look on their way to restoring a healthy birth/death ratio within a few decades.
Meanwhile the US birth rate doesn't seem to be tanking from online dating[1]. There has been some decline since 2005, but it seems to be bottoming out and is still well above 1975-1980 levels. In the grand scheme of things that's just normal fluctuation [2]. Of course 1.85 is still way too low to be self-sustaining, but Tinder doesn't seem to be the problem.
The EU fertility rate seems similarly unimpressed by the advent of online dating (being above the levels of 2000, but still uncomfortably close to those of Japan) [3].
If there's an apocalypse, it's the one caused by wide availability of the birth control pill. That really upset out demographic pyramids. Online dating meanwhile doesn't seem to have any measurable impact so far.
Of course, that's only a real problem if our immigration policies continue deteriorating.
[0]https://en.wikipedia.org/wiki/Demography_of_Japan]