Anxiety: it's stone age tech in an iPhone world
Talking about people "having anxiety" is an odd way of phrasing it. It's akin to saying "people need water".
If you are a living human (if you are reading this then I will assume you are, if not please do let me know) then you will experience anxiety, just like you will drink water. And just like water, too much anxiety can be overwhelming.
Anxiety is built in
Have you ever been startled by a loud noise? Jumped at a horror movie? That's anxiety. What we call anxiety is our natural defence mechanism, often called fight/flight. It's there to keep us alive, safe from all the myriad dangers we can face, and it's very much a "shoot first ask questions later" kind of system.
When it does its job anxiety turns you into a super you. Optimised to run faster, hit harder, see further and survive better.
Stone age technology
The problem is that our incredible threat response system is pretty old, based on the kind of threats we might face shortly after we pulled ourselves out of the primordial ooze. For these threats it's ideal. sabre-toothed tiger coming at you? Fine, release adrenaline and get the heck out of there at top super you speed. A rival trying to take your hard won dinner? Fine, release adrenaline and unleash your supercharged punch to the jaw.
Your partner leaves you and you can see yourself alone and unhappy forever? Release adrenaline and... Oh.
Here's the problem. We made a terrible mistake as a species. We got smart.
Try texting an abacus
Our brain is amazing, astoundingly, unbelievably clever. Humanity has the ability to imagine, to think. We have created incredible art, gone to the moon and cured diseases. That's great, but also a problem. It's a problem because this incredible system has been mashed on top of a stone age bit of kit. Suddenly we can worry about something; we can see ourselves being laughed at by everyone, we can see ourselves ostracised, cut off from the herd, cold and alone. We can imagine it happening.
And that is a threat too.
A threat that pumping out adrenaline is unlikely to help. But it's what we do, our threat system has only one response. Logic and reason can help only so much, that's the language of the smart part of our brain, not the language of our stone age threat system. It's like using your iPhone to talk to an abacus. It doesn't work.
Learn the language
It is possible to communicate with our threat system. We can teach that old dog new tricks. More accurately we can teach the old dog to do its old tricks only when appropriate. CBT works with these kind of issues all the time, literally every day of my working life I work with anxiety. It's about learning, gently and slowly. There will always be an element of challenge, but like any learning it needs to hit that sweet spot just above what you can already manage. Keep doing that, and learning happens pretty quickly.
Anxiety can be understood and reduced.