There is no way I'd consider any 'cloud based' back up solutions for all of my images and other personal files.
Especially not the likes of Microsoft's One Drive, where I believe you effectively have to waive your right to thinking any of it will be private, by ticking the terms and conditions to be able to use the service.
But I've uploaded a small number of images to ImgBB just for the purposes of posting on Bluelight. AFAIR everything I've uploaded is still there years later. But I wouldnt upload all my images there or anywhere else online. I dont care if the images that I have uploaded to ImgBB are scanned by AI or w/e, after all I've already posted most of them online publicly anyway. It's a free service, and password protected. You can choose to let people follow your account and see your content, or not. But I presume the hosts and any hackers would be able to view the images anyway. Plus where you've stated certain sites are removing 7OH or porn pics obviously shows that they aren't private accounts.
Going off an a tangent now sorry, but if you're thinking about all this as some kind of method of backing up your images, it seems there are issues with most physical back ups also, USB stick drives are notoriously unreliable, and I'm now finding out that even the very best rated and more expensive higher quality SSD drives are not good for long term back ups. Apparently, they are better for daily or at least regular use, and don't like being potentially not used for years or months until you might need the back up, and may find everything gone, when the time may come that you need the back up.
The best solution apparently is using additional internal hard disk drives. But that means opening up your device and physically connecting and disconnecting the extra HDDs every time. Which is hardly convenient. Unless you keep the case off your PC or just loosely attached. But even on those I believe the quality degrades over time, just as it does on CDs and DVDs.
Honestly for all it's positives, it seems that the digital world can't even find reliable long term storage solutions, that maintain the quality of the files, unless they are cloud based. But these solutions are expensive and as I say they are also not private.