Snowden said directly, twice, and it meshes with my own speculation from having worked at two of the implicated companies, that PRISM is the NSA-side codename for an efficient warrant process and nothing more.

Calling them warrants when they are issued by the FISA rubberstamp court (or are NSLs) is quite a stretch.

Collecting metadata doesn't require a backdoor.

There is tons of evidence that putting a name in your iCloud or Google contacts means the NSA gets a copy.

Please cite the iCloud evidence to which you're referring.

The entirety of the evidence for the very specific claim you made is a single slide with the word "Apple" on it alongside every other big tech company?

Better assume they are backdoored and every communication and stored information is accessible by govt and its organizations. That way we would be conscious about our activities on devices and elsewhere and try our best to protect ourselves until the system changes (which could be never).