There is an increasing amount of Rust being incorporated into Firefox, it is just not Servo.
And while it is possible to develop two browser engines at the same time (though it is not surface area, it is a different module competing for the same spot, so no, I’m not contradicting myself), it is still a dumb decision to split the already few people with the necessary technical knowhow around such an advanced domain. Otherwise you would see thousands of browsers out there, yet all we have (ones that implement a reasonable amount of the web standards) is chrome+edge, safari and firefox.
And while it is possible to develop two browser engines at the same time (though it is not surface area, it is a different module competing for the same spot, so no, I’m not contradicting myself), it is still a dumb decision to split the already few people with the necessary technical knowhow around such an advanced domain. Otherwise you would see thousands of browsers out there, yet all we have (ones that implement a reasonable amount of the web standards) is chrome+edge, safari and firefox.