It depends what you want to do and the amount of polyfills/backwards compatibility you need.

Nowadays most projects use one of the big frameworks like React/Vue/Svelte and others which take a vastly different approach to maintaining the DOM and for the most part you never manipulate nodes yourself, therefore you don't need jQuery and it's not used much anymore. JSX is weird at first but it's actually quite nice. Some of those libraries like SolidJS have impressively low overhead.

And for those that like to stick to just minimal JS, the browser APIs have matured a lot so a lot of jQuery isn't really necessary anymore either. We have querySelectorAll and things like Array.prototype.forEach and Array.prototype.map and arrow functions that cut down a lot on what shortcuts jQuery would offer. Visual effects are usually done with CSS animations and just switching up classes. Everything AJAX is easier and cleaner with the new fetch() function and accessories. Vanilla JavaScript is for the most part quite usable and easy these days. You can even create custom HTML elements from JavaScript to make your life easier!

But if you're looking at the jQuery API specifically, you can still use jQuery today. It's still maintained and functional. I think modern versions are pretty small too since it no longer needs half of it to be Internet Explorer hacks and other obsolete browsers that were holding web development back.