How can I get money from web design?

Websites still need to be built to be viewed on mobile phones/tablets.

Agreed, most companies that want a website are going to also want you to make it responsive for mobile and tablet devices, there is still a big market for web design you just have to network and get your name out there. Another big web market is development with Ruby on Rails, PHP, Django, and .Net so look into that as well.

I view websites and blogs on my mobile phone too.

It's very hard to get good webdesigners/developers with a decent quality/price relationship. I always enjoyed programming but I studied structural engineering. Meanwhile I had a lot of projects on my mind but not that much money to invest. I realized that the prices were way to high for the quality delivered and rarely you would have any guarantee of a job well done. I just recently started to study and I already have clients. But this is like others businesses. If you will try to do everything for yourself you won't go far. You need to think big and try to delegate tasks as soon as possible to keep productive and profitable. One thing I've noticed is that the current freelancing websites are very bad both for the employers and the employees. It's a time waste looking in a website full of spam.

And I disagree that most people don't want to do blogs. Now more then ever the web is overflown with blogs and websites. You have to be smart to sell because many individuals will now opt for a wordpress or blog at zero cost. People that want to create a real income in the web will need a webdesigner/webdeveloper or learn themselves to survive in mid/long term.

Hey Suli check out the 'How to Freelance' and 'How to build your business' courses in the 'Business' section. Web design is a booming industry, even more so with the shift to mobile & tablets. It's evolving not disappearing, the trick is to ride the wave.