Servo produced a very fast CSS rules matching engine now used in Firefox (see https://nolanlawson.com/2022/06/22/style-scoping-versus-shad...), and WebRender which underpins Gecko's rendering. That's not nothing.

About embedding Servo, I have some experience around that (https://github.com/fabricedesre/servonk/) and it's been easy to embed: you just need to provide a GL surface and hook up your input events into their event loop. Clearly there were not zero integration points, and a some other examples exist (like https://github.com/paulrouget/servoshell).

Components of Servo were integrated just fine into Firefox. WebRender is the big one, and iirc many smaller ones too (the css parser maybe? memory hazy)

There's also non-web-related software that uses WebRender, such as Azul. https://azul.rs/

Maybe there aren't integration points at the layer you were hoping for, but that doesn't mean the entire project is "bullshit"

Servo supported the CEF (Chronium embedded framework) API for embedding. See https://github.com/paulrouget/servoshell and https://github.com/jdm/servo-embedding-example