I think you’re a little harsh describing it as a scam, but yes you have to be aware of who you are trusting and what the risks and failure when using this type of service, including the security risks.
Of course there are also risks with self hosting, depending on your competence and the service.
I have a Vm on the cloud I use for running nightly nmaps against my network range, when that breaks it’s not the end of the world, if the VM provider hikes the price, or goes bust, I can migrate it in an hour by running a script, thetr no sensitive information on there, it makes perfect sense to run on a VM.
Would I entrust my journalist’s files when they are investigating corruption in Amazon? No.
If all of the above is true, is it time to panic? Perhaps maybe that why the cloud is somewhat of a scam anyways?