Why coders are paid well, What is the difference between front & back end?

Definitely being expert in the Back-End is more interesting because you'll have to deal with scalability issues and big databases with millions of rows and this will push you to optimize your code and queries (maybe use caching) and also maintainablity of the code will push you improve your architecture (maybe using micro-services). In the Front-End, there is no bottle necks to tackle, the only concern is to have a maintainable code to facilitate adding new features and this is what the js frameworks are for

So more important than deciding between Front-End vs Back-End you have to understand how they interact with each other. I feel back-end more oriented to programmers who usually like to do complex algorithms usage and focus on coding. I'm not saying front-end doesn't need programming knowledge, but it's more focused in user experience (UX/UI concepts used a lot these days) and the aesthetic. You usually see the web designer + front-end combo mostly on designers and then the back-end + front-end combo for programmers. The real deal is dealing with your trade (be it back-end or front-end) while still being able to see what's happening on the other side of the game.

I have the impression that there are a lot more front-end developers rather then back-end developer, simply because back-end is much more complex and difficult to learn. I also have the feeling that as a consequence, there are a lot more offers (with higher salaries) for back-end developer then for front-end developer. You get get amazing website templates for 20$ and then you need someone who brings them to life.

Big companies are often looking for full-stack developers, rather than front- and back-end developers, so you're "forced" in a way to know both. Of course you have to specialize, but without knowing both, you reduce your opportunities to get jobs. And we shouldn't forget that front-end developers are paid less, than back-end devs. And it's obvious, because back-end is much more complicated. The companies have an impression, that front-end can be done by a teenager with no prior experience, where the back-end is more complex in their opinion. Especially when it comes to big data