With a component library, you have to code less, both in CSS and React. With Tailwind you can do it all by hand but it will take more effort even with all the CSS classes written for you. The two approaches are not really comparable.
If you want to focus more on the core of the React app a component library might be the right approach to take, you will give up some control in return for more premade code. If you want more control Tailwind is still able to greatly assist in not having to write so much CSS but you are also required to write more components yourself.
Apps written using component libraries tend to look more similar, with Tailwind you can make it look more custom.
Learning Tailwind is a good idea so you should look into it at some point no matter what.