For example Google and Meta both scan all material that is on their services, both of these providers actually go further by utilising AI to hunt imagery which may not be identified yet. So the idea of this compelling others to scan is false: Apple is last here.
Similar to Google and Meta, Apple's CSAM processes only come into play when the material is uploaded to Apple's servers. The minutiae of where the scanning occurs is irrelevant because Apple's implementation is merely a way of performing the function without giving up the user's privacy (by scanning locally rather than sending all of your photos to Apple's servers for review.)
The scanning process is merely the addition of verified hashes to a system which already uses this same technique to categorise ones photos into searchable images ("waterfalls" "dogs" "bicycles" etc.), because this is an existing system there is no impact to performance/device usage.
This is where you and I part ways. I don't think that's an irrelevant minutiae, because it normalizes on-device scanning. This implementation or others may change in the future and opposition to those future implementations will be hampered by "Apple was already doing it" arguments, which will sound fairly plausible to the non-technical public.
Maybe I'm making a 'slippery slope' argument here, but I've become comfortable with such lines of thinking. My cynicism has been rewarded too often before.
That depends on how "BYOD" the company is. There's an awful lot of companies that provide work machines that most of their employees reasonably use for some sort of personal work, be it checking their bank statements to see if they got a deposit or logging into a handful of services so their settings sync. In my opinion it is unreasonable to expect people to not do this, especially given that the alternative is quite painful with modern software. Corporate searches have a problem of not really having clear limits like a legal search might, so going through e.g. your synced web history when trying to find evidence of credential abuse (check your own audit logs!) is common.
The objections come when such systems are to be run not on corporate property, but on end user property. I don't see anybody objecting to corporations scanning content uploaded to the corporation's own computers. Scanning content on the user's computer, which is the user's property, is what unnerves people.
Furthermore, while Apple may have implemented this feature in a relatively safe way (I don't fully understand it so I'm not confident of that, but smart people here think it so I'll assume it for the sake of argument), I believe that the general public does not really understand this nuance and Apple normalizing the practice of scanning personal computers will clear the way for other corporations to implement scanning in shittier way. If Microsoft were to start scanning all documents on a Windows computer by uploading those documents to their own servers, is that a distinction that would necessarily be made clear to the general public? I don't think so. The rhetoric will be "Apple does it and that's fine, so Microsoft can do it too". The technical differences in the two implementations will be understood in forums like this, but not by the general public at large.