It's fine to use jQuery, especially in a WordPress environment where it's included by default. But it will be very beneficial if you learn native JavaScript.
Does a WordPress developer need to know Webpack? You might think it is unnecessary and too complex. So I will show you how useful it is for developing a theme.
Update 11 Aug 2020: WordPress 5.5 introduced native lazy loading by adding loading="lazy" attribute to all images. So you no longer need to create your own. Lazy-load is a way to prevent…