He started out doing challenge videos like “counting to x” and it was literally like a multi-hour long video where he counted to 10,000 I believe. It’s insanely boring but it showed his “dedication to the bit”. Another is saying " pewdiepie like 10,000 times. I may have exaggerated, I’m not at a computer to look up the numbers. Eventually, after tormenting himself and gaining some followers and he got paid some money from youtube. With his first paycheck he made a video of him taking that check and giving it to a homeless person (IIRC). His philosophy was always to take any money he makes and dump it right into the next video. This has allowed him to slowly make bigger and bigger videos. He still regularly does challenge videos (buried himself alive for multiple days, not eating for several days, etc.) But, him dumping all of the money he makes into has grown from giving his first, probably couple hundred dollar check, to a homeless man, into giving literally millions away per video.
He also kind of pioneered the thumbnails you are talking about. And yelling at the beginning of the video to grab your attention by showing enthusiasm was also really his thing too. I mean some people had probably used it before. But, he used it regularly and had the type of content that really was that exciting.
Whether you care for challenge content, giving away money, some combination of both, or neither he also has Beast Philanthropy. That’s his channel where he does good “because he can”. He puts a bunch of money and gets sponsors to give money for causes like, building wells, building houses, paying for surgeries, building hospitals, etc. I thought it was a bit gross to make videos out of charity work at first. But, it helps a lot of people in my deserved countries, and raises awareness to then and the charities that try to help them. Also, all the money they make on that channel goes to the charity of each episode.
That was more than I thought I would type for sure…