Servo's history is much more complicated and originally was planned to be used for the holo lens before the layoff. Comparing trajectory doesn't make sense they had completely different goals and directions.

What are you talking about? It doesn't have a "browser", it has a testing shell. For a time there was actual attempt with the Verso experiment but it got shelved just recently. Servo is working at being embeddable at the same time when Rust GUI toolkits are maturing. Once it gets embedding stabilized that will be the time for a full blown browser developement.