Comment by devsda

If we are saying "secure", we should talk about what we are securing and against whom.

A smartphone may be secure against malicious individual actors but its certainly not the most secure when it comes to your private data. Modern day smartphone is designed to maximize capturing your private information like location, communication patterns, activity and (sometimes) health information and pass it on to as many private players(a.k.a apps) as possible, even to governments without your knowledge. You don't have much control over it.

In that aspect it is less secure than your typical PC. A PC doesn't have that level of private information in the first place and whatever information it has will leak only if you opt-in or get infected by malware.(recent Windows versions without necessary tweaks may be considered a malware by some).