It's not. It depends on how open the phone is and if it relies on exploits to root or if there's an official method. Pixels are open and you can just install whatever you want on them, with open source drivers (although Google is trying to stop that too). So to install Graphene, for instance, it's literally a web app with one or two clicks to do it automatically.

[–] Snapz@lemmy.world 2 points 4 days ago

Agreed, some very talented and generous people worked to make it easier and easier, but less options over time when manufacturers started dropping and phones all consolidated and locked down more and more. Even when it was more complex in early days, and greater risk of a brick, you could often restore back to a stock ROM or dual boot in a way so actual risk was minimal if you just slowed down and followed directions - again provided by very generous people who just wanted to make things better.