I'm absolutely not against combining the two in one (good) wallet.
Also I don't see a problem with the two separated.
I have my life savings on chain.
It is literally my own bank.
LN is my wallet, where I keep money for day to day expenses.
Why would you need to bring your own bank (saving account/ life savings) with you all the time ?
Plus the risk it adds if you make it that accessible all the time 🤔
Now I give it a thought, I will keep the two physically separated.
But a third layer in-between could be useful ?