The recent Unity-Godot debacle would seem to indicate to me that titans aren't invincible. They can do a lot of harm to themselves when they overestimate how much people want or need their product.

Switching from Chrome to Firefox isn't even nearly as difficult as switching from Unity to Godot (or say, from Windows to Linux). For the average user, Chrome and Firefox are functionally identical. If Chrome kicks off Adblocker, Firefox will be obviously better for a lot of people.