I don’t think it’s about them losing your files. It’s not trusting what they do with them.
Ok, fine, you don't trust the safeguards Google as a provider of cloud services has in places. That's not unreasonable.
Why then would Canon's offering alone, or paired with another provider, be safer? Do you even know whose cloud Canon's data is stored on? Because I guarantee they're not running their own physical datacenter.
Could be AWS (Amazon) or Azure (Microsoft), could be Google, could be any number of other providers.
Do you understand transport security/encryption from end-to-end, and which ones the three letter agencies of the US and other countries have either broken into or have a backdoor into those networks? Or how absolutely boned your home router probably is (if someone wanted to get your traffic), or your cellphone if you use that for any data transfer?
I'm not really sure what the concern is specifically with what Google could do with the photos you shoot, but I'd be interested in hearing what that is, and what cloud solution you prefer to Canon+Google.