The last sentence doesn’t follow from everything before it. You could have said that it increases some risks, but decreases other risks. That would have been accurate.
And this is the point, right? Many people want to use alternative operating systems on their phones so that they aren’t vulnerable to Google itself. This itself is a massive reduction of a certain type of risk.
What difference would that make? If someone who does have big guns wants to take them out, they’re going to end up at the bottom of the sea regardless of how clustered the boats are.