He made neither the browsers nor the servers that people used, and libwww was so full of bugs and memory leaks that it was heavily modified by those who did, if they used it at all.
The W3C was its own thing.
At some point, you do have people that need to step back. If you turn it over to another single person, they could pivot and "ruin" the product. By turning it over to a committee, hopefully, any ruinous ideas get overruled. At least in theory
Keep in mind that every for-profit publicly-owned corporation has many shareholders, as well as a board of directors, which is, gasp, a committee!