OK, let's be honest- nobody wants to see a couple full on swapping saliva down each other's throats and pretty much having sex with their clothes on, but what is wrong with holding hands, cuddling, and kissing?
Let me just tell you that when couples are displaying their affection, they aren't doing it so you will look. They aren't doing it to make you jealous. In fact, they're doing it to show intimacy with their partner. The last thing that couple is thinking about is what your opinion is.
Who cares if someone is holding hands with their SO? Who cares if they exchange a kiss on the lips? If you're really bothered THAT MUCH by PDA, go do something else. Don't like people posting about their SO on Instagram? Lucky for you, there's this invention that lets you unfollow someone so you don't see their posts anymore (it's the unfollow button p.s).
Saying you're bothered by people holding each other, holding hands, and cuddling makes you sound so ridiculously bitter. Do you projectile vomit when you see a couple walking around in public holding hands? (P.S. Being bothered by a couple holding hands makes me think you'll be one of those elderly people who hates to see anyone have fun)
I hold hands with my fiancè everywhere we go when we're in public. Hell, we even hold hands while we're driving. Even when we're in public, we'll occasionally give each other a peck on the lips. Do we stand there and make out and shove our tongues down each other's throats? Definitely not. There's a time and a place for that and out in public is not the time nor the place.
PDA is exactly what it stands for: public display of affection. The affection, however, isn't for you. I'm not expecting you to get excited or start jumping up and down when you see a couple kiss while you're in the park. If you're not in a relationship, you probably won't understand that it's nice for your partner to display affection like a kiss on the cheek, a hug, or cuddling or whatever the case may be.
Seriously, though, there are bigger things in the world to be bitter about. There are bigger things in the world to be jealous of. Seeing a couple display their affection is not one of them.
Please tone down your jealousy. It's annoying and gross.