Earlier quoted context omitted.
Why would you use browser-based video editing over desktop-based free software, where you can read the source (or listen to someone you trust who has read the source) to make sure it's not doing anything malicious? Besides the fact that it might be easier/simpler for very small projects.
Because then it wouldn't be "cool". So many of the projects I see mentioned here are neat hacks, but that's really about it. People writing a complete operating system for an 8 bit micro made of discrete chips? That's neat, but not really useful, and most people won't ever take the time to boot it once. An FPGA that runs web assembly code? That's nifty, but if we want high performance we probably won't use web assemb…
Pure interest and sublime pointlessness are, of course, two of the classic hacker motivations.
Edit: https://news.ycombinator.com/item?id=23246221 is happily near the top of the front page as we speak.