Other platforms with ads haven’t really seen people move off those platforms. I feel like once it reaches that critical mass of being nearly ubiquitous it takes a massive problem to push people off of it. Look at SMS in the US and how it’s refused to die compared to other markets because it has reached saturation and now the only challenge to that ubiquity is iMessage who basically lives off being a fake SMS service.
Getting so low the old power bricks laptops often use will make a bigger impact in power use.