I think there is a fundamental difference you're missing between the experiences you're describing and that of online dating: it's not so much about the amount

I think there is a fundamental difference you're missing between the experiences you're describing and that of online dating: it's not so much about the amount of noise and more about the signal-to-noise ratio, as well as the overwhelmingsness of the situation that the author argues makes dating websites (not life in general!) a difficult experience. On a dating website, messages are the only signal available to the receiver. This means the person had to go through a lot of noise (or as the article says, "wade through a mountain of shit") to find out if anyone interesting to them messaged them. If on top of that these messages are as numerous and off-putting as the person in the article says, then it's easy to see the online dating experience can become rapidly unpleasant. Furthermore, this is a problem because finding matches is the only function of a dating website! Now, back to your example. The thing is that not only do you hopefully get utility from socializing at a bar beyond being able to find sexual partners and you're presumably not constantly in such a situation (which already makes your analogy miss the point), but you have many other signals at your disposal: you can simply visually identify those who are more attractive to you in the room and physically make your way through them, and even though, as you said, you can get cockblocked at times, this is still an option that's not available to people on dating websites.