Greasemonkey had a ton of user demand, but also had a low ceiling.

Greasemonkey was an extension in Firefox back in the day that allowed users to install little content scripts to add features to sites they used.

It was powerful… but also dangerous.

Greasemonkey was a power-user feature, and could never scale beyond that.

It required users to be a power user to install it in the first place.

But it also required users to be a power user to audit and get a sense of the danger of scripts they installed.

MCP seems similar to me.

Tons of momentum among power users and in the ecosystem, but fundamentally presumes a dangerous, high-friction tool.

A forever power user ecosystem.