Is there a better alternative? Does something like a wordpress theme support proper scrolling out of the box? I am working on a blog and know next to nothing about this :)
You don't need "support" for scrolling. It is supported by the browser, out of the box. The website hijacks scrolling with JS by introducing "smooth" scroll, which is a big no from the UX perspective.
What they think is "smooth" then feels like "my finger is wet and the screen isn't properly reading swipes" on a phone.
Your readers will have picked a web-browser that supports scrolling the way they like it. The less you try to interfere with the way people choose to visit your webpage the better.