In fairness, while there was definitely Mozilla mismanagement, there was also a massive monopolistic marketing/bundling campaign by Chrome. Google search and other properties pushed Chrome, Google paid application publishers to bundle Chrome the way they bundled adware, and so on.

Servo never had. But yes, mozilla management let FF go down the drain.

Servo was not intended to replace Gecko. By all reports it was an experimental component, many of whose findings were used in Gecko.

That folks want to take it further is admirable. But doubtful Mozilla could have afforded to with their existing commitments.