I don't think that the web is complex, at least not in a sense I'm understanding "complexity" word. Web is a huge pile of semi-specified standards. There are bunch of written standards, like XML, HTML, DOM, JavaScript, CSS (each with multiple versions). There is a lot of tribal knowledge, that you'll get only with experience, like things that doesn't work with IE 6 (luckily IE 6 is not very relevant today). There is some security-related stuff, things that you should remember if you don't want to make a vulnerable website. But it's not a complexity, it's just a lot of things.

Now there's a bad tools. JavaScript is a bad language and its ecosystem is mostly terrible. If you want to create react app with hot reload using es6 and other things that modern developer expects to have, you'll end up with tons of configuration glues, some experimental hacks and many tools hacked together. Or you can download "starter" template, where those hacks are already glued for you. Good luck to add or change or fix something there. In contrast I can write very simple maven config and it'll support almost everything I would ever need without any configuration. It's difficult to navigate among those tools, but this difficulty will be solved with better tools and better documentation. I'm eager to wait until I can throw webpack and just write ES7 with imports and browser will understand it. I shouldn't need build tools for web.