Online dating sites/apps seem like they'd be a nightmare.
So right now it's pretty much considered impolite / not socially acceptable to ask someone out except on dating apps. This is definitely a downside.
But the upside is that a match on a dating app is an explicit acknowledgement of mutual interest, so it's clear that you're meeting up to go on a date and not just hanging out.
Says who?
Says who? Have you stepped out during a weekend in a US metro city? To popular nightspots? No app needed to meet and socialise with attractive people - strangers or an extended social circle. In fact some might even say it is like shooting fish in a barrel
If by “some” you mean females in their mid-20s, then yeah probably.
Just make a move in real life
The problem with dating app is exactly what you mentioned: if you both know you're there to date or fool around there's no uncertainty, no tension.
You're missing out on the feeling on trying to pickup a beautiful girl and succeeding.
Besides, girls, unlike boys, compete mainly on looks. It's natural dating app will break the balance in favor women, and that's exactly what happens. Men have a tenth of the matches and are selected by women according to beauty standards instead of being evaluated by their behaviour, providing a terrible filter for dating. If in person you had a chance with some jokes and some confidence, you'll never pass the selection with that nose.
For every happy story used for supporting said model, there are literally billions that did it the old fashioned way.