All of these "features" are opt-in. If you want to use iCloud you now know that the hashes - which give no information about a picture's content - will be checked against known hashes of content violating CSAM policy, which is highly illegal in most countries (and rightfully so). If you don't want that don't use iCloud. Messages will be checked only if you configure this for your child. If you don't want that - don't do it.
And sorry, the argument that Apple could abuse this system if they wanted to doesn't fly since if they wanted to they could backdoor your phone with the next update and nobody would notice until the damage is done. The same is true for Android, or literally any non-open source operating system running on any networked device. Everyone who's the least bit informed knows this and has either widely accepted it, or has opted out of using closed hard- and software. Alternatives do exist. They may not be pretty, and may sometimes be impractical, but they do exist.
The question is: is it in Apple's interest to do this? Is Apple willing to risk its reputation, which is the foundation of them earning three digit billion dollar sums annually? The answer is: no. It is not. If widespread abuse of this kind would become known - and it would become known, since hardly any company has so many eyes on them and what they do - it would cost Apple tens of billions of dollars.
Apple's business is sales-driven, and despite them being highly profitable they only occupy a niche in the industry. They are not in the business of selling your data. They are in the business of selling you highly priced boutique hardware and highly priced services. You can refuse to fund them at any given moment. You can't refuse to fund Google unless you decide not to use the internet since they practically own it.
Apple does and will continue to do what is best for their business. They follow the capitalist mandate rigorously. And this means they will not abuse this system or any other since it would cost them money. More money than any company or state could offer them.