Apple has reported they they will start blocking Facebook’s web-tracking tools. Last time I check about 25% of cellphones and presumably Facebook users use an iPhone.
With Google being in competition with Facebook and Apple, it doesn’t seem that far fetched for Google to do the same with Android. Seems like this could have noticeable effect on the data they can provide ad customers and in return lower the value of their ads overall.
Apple just said a few days ago that it was looking to expand its ad business. Funny how this came right after that.