People need to be cautious with all of their downloads. Their devices, computers, phones can be infected by download other things beyond cryptocurrency wallet softwares.
If they download unofficial ones, they have bigger risk of get phished by fake applications and infected with malicious components that can steal many sensitive information on their devices from computers to phones.
When a device is infected and there is sensitive information in it, like a file that store account password, wallet password, mnemonic seed, wallet file, there is big risk to be stolen cryptocurrency stored in that device.
I totally agree that people need to be very careful when downloading apps especially for cryptocurrency wallets. If we download wrong app it can cause big problems like stealing our personal info or cryptocurrency. We should only download apps from trusted places and check them out first. We should also use antivirus software and keep our device system up to date to stay safe. Losing our cryptocurrency because of bad app is big risk so we should take steps to protect yourself. Otherwise the scammers have many methods too steal our money. So we should always be careful.