I was thinking about YouTube, where a lot of channels started off as people filming from their parents houses or dorm rooms and have become full-fledged professional productions. I’ll probably do a longer version of this eventually, but here’s one thing: all of Marques Brownlee’s videos, from beginning to end. He’s an incredibly detail-oriented filmaker who now is at the top rung of filmography on YouTube - using extreme high-end cameras like Red & advanced processing, and the highest possible HD output.
But he started in 2009 with a HP Pavillion review and a webcam. These are all of his videos, in chronological order, for the first 10 seconds. You can see things start to develop: gestures, improvements in lighting and framing. Title cards get more compressed and perfected. It’s cool to see people mastering an art.