Naturally, providers and large data warehouses do introduce many fail-safes.

Storage is a more complicated issue, as with multiple devices accessing the same stored data, credentials usually have to be stored somewhere too.) (Unlikely with end-to-end encryption, but that usually concerns communications. Of course, a responsible provider will secure your data in more than one way, not only by hardening their servers/services but by storing everything encrypted, which is probably the best possible way, until said hackers get their hands on the encryption keys. The late scares of meltdown/spectre have also mostly meant mostly your cloud storages were/are in danger. A large-scale hacking attack will most likely target large cloud-based data-centres, where the attackers are most likely to get access to tons of information, some of which might be useful for them. There are, of course, inherent security risks involved. Cloud storage is mostly transparent these days, and even mobile bandwidth provides mostly instantaneous access to whatever you are accessing, but Cloud storage still inevitably means to store your stuff on remote servers, God(s) know(s) where. The root cause of the problem, which restricted data access is a symptom of, is data storage, and how most cloud-based apps handle this.

Cloud (in)security is not always your friend TagSpaces, the application of choice does many things right but surely is unbeatable in one particular: Data access. Soon after publishing Five Evernote alternatives, and how to preserve them in brine (this might not have been the exact title), I have settled on one of the contenders from the same list. My quest for a suitable Evernote replacement, after the company decided to restrict access to my own data, proved to be a short one.

Evernote web based