I doubt you'd invest that kind of money/time into a project without a good reason. I am not saying that ladybird or manifest v3 are the reason, I just notice a lot of new energy in the not-just-chrome category and wonder what the other reasons might be.
Andreas Kling is pretty open about his reasons to have started the ladybird project and I just know Servo from his monthly videos and a few other sidenotes, so I was surprised that it gained so much traction after being basically dead.