These are 3D animated videos It takes a lot to create something like this. Normally a single video like that takes 10 days for animation itself by more than 5 peoples working 10 hours a day. Then you have to light the scene, which can take over 3 days with more than 3 artists. Then, renders take time. These videos take time to render..almost 3 to 12 minutes per frame. Now, a minute has 25 to 60 frames depending on the framerate of your video.
Look, prior to making this video, the studio has gone through the process of bg (modeling) , character modeling, rigging (adding bones to those characters), textures etc .
In few words, you can't make it by yourself..either you outsource it to people like me or have your own team of atleast 20 people. You need to have a budget of $3000 to start making those videos (including salaries of people, cost of electricity, time etc) . This is no joke..
I have made these videos (lighting artist) for 3 years. You won't earn much due to stiff competition on YouTube. You'll need a hefty budget just to get your channels more exposure.