My father told me he wanted to make USB flash drives of all the scanned and digitized family photos and other assorted letters and mementos. He planned to distribute them to all family members hoping that at least one set would survive. When I explained that they ought to be recipes to new media every N number of years or risk deteriorating or becoming unreadable (like a floppy disk when you have no floppy drive), he was genuinely shocked. He lost interest in the project that he’d thought was so bullet proof.
There have been plenty of cloud services that have shut down and taken their data offline. And plenty of current ones deleted data after users have gone inactive. Or require constant payments to keep accounts active. Cloud, as it exits now, is not the answer to the archival question.