Hiding apps on mobile devices is still not safe i just agree with hard ware wallets or paper wallet as safest except for urgent transactions a small fraction can be transferred across mobile wallets for immediate transaction.
This should be a proper way to use bitcoin wallet, it does not even matters you should get a hardware wallet, but if you have some extra dollars to spare or have a amount of bitcoin, you can buy one for convenience sake and use it, instead of online wallets. But paper wallet can be used too, not for making transaction everytime but for storage, the coins that want to be used daily for transaction can be moved to online wallet, but with privacy and security in place. For this later, someone may not have a computer and just need a mobile phone for it, but not advisable.
When it comes to malware, Spyware and the likes, desktops are more at a risk of catching this viruses than mobile phones, desktops can easily download documents, apps and all sort of files while you browse or have data connected, even without your knowledge.
Using desktop wallets,( without adequate and proper security softwares installed and running) is far more riskier than using mobile wallet.
I will say no. Both mobile and desktop wallet are online and they are both risky, but because people are taking phone around and to everywhere they are going makes it more prone to attack.
Malware are just in kilobytes, both desktop or phones can easily download it in less than a second.
If using any, you have to be careful of malware and avoid your device from downloading malware. Phones will also download malware even without the owner knowing.
I've see it where people are entering their passwords or pin numbers right over a security camera. I'm not saying that the security camera owner would even look, but for me it's a glaring security issue that you wouldn't get with your computer, since it's very likely you're using your computer in your own home.
If you take your wallet outside of your home, it is more prone to attacks in my opinion. I would rather prefer my home (personal) computer for little amount of bicoin for frequent transfer while I can only use mobile phone for the amount I can be able to lose because anything can happen because outside is riskier and the wallet is still an online wallet. But I do not make use of phone for wallet again.
You know, the smartphone I use has this feature that I can activate that makes my phone unlocks itself whenever I'm around a certain area. However, it scares me to activate and use that feature till date.
That is just it, I can never even do that. The easier the usage, the more the device is less secure just like everyone using fingerprint today to unlock both phone and the wallet on the phone which is an easy way to steal.