I prefer to keep my coins on different platforms and ofc physical wallets are preferred but I am not a stickler on that point when it comes to ease of access.

Have you heard the saying don't put your eggs all in one basket? 

Cryptocurrency will never match the security of a brick an mortar bank from the 20th century.  Mistakes happen.  Developers are not perfect and bugs are a reality.  Hackers find and exploit these bugs for their benefit.  But most likely it will be some sort of user error.  Keeping all your private keys and passphrases on a laptop, open a webpage and viola you have just installed a malware program and lost all of your files and soon your cryptocurreny.

I find the most stable/reliable wallet for a particular cryptocurrency and keep my funds there(ease of access like I mentioned).  Same goes for my backups.  I keep them in different places using different mediums of storage.