Really? Apple and Google have been able to scan content on your phone as long as they have sold phones. They control the OS, therefore they have access to the content. The ability has always been there. The only difference is that Apple has now openly announced what they are going to do and how. If governments wanted to pressure Apple (or Google) to scan content they could have done that anytime in the last few years. If Apple and Google resisted that before, why is now different?
From a legal perspective, there is a significant chasm between "you are hereby ordered to develop a whole new surveillance feature for devices you build" and "you are hereby ordered to add these new (potentially unrelated to CSAM) signatures to your existing surveillance network".
> Google does reporting on how many National Security Letters requesting information about it's users that it responds to annually.
So does Apple[1]. Apple gave data on over 31,000 users/accounts based on National Security Letters in the first half of 2020 alone[1].
> Why doesn't it just ignore them?
In the first half of 2020, Apple provided data to the US government (non-FISA or NSL) about 9,000 times, and responded to requests for data with the data about ~85% of the time, and 92% in cases of "emergencies"[1].