I can only tell you about my personal impressions:

    * Google has a lot power. Many Web-developers seem to think that "Chrome is correct" and other engines must behave the same. I'm questioning this.
    * Apple locks-down their devices. This is not acceptable, because the customers are the owners of these devices. As a side-effect - this prevents a complete dominance of Google's Blink Engine.
    * Google is pressing on every user of their website "Install the Google Search App", "Install Google Chrome" and especially annoying on iOS is Google Maps which constantly tries open the App-Store (somewhat also Apples fault?)
    * Finally Microsoft Teams allows using their website only with Edge (Blink) or Chrome (the original UI for Blink). So we're back in 2001?]
    * Opera, Trident and KHTML no longer maintained.
    * Other than WebKit the Gecko-Engine seems not be used often as integratable  engine. There was Galeon but replaced by Epiphany.