I hold many coins but i don't store all of it in a single wallet because what if you misplace your key to open that wallet then all of your holdings will be gone in instant. I rather spread all my tokens and altcoins in different wallet to have better security of my holdings.
That's correct, not only we diversify the risk in investing by spreading our money in different coins, but we also have to store it in different wallet.
It's the best strategy especially if you are investing for long term, might as well put it in different places so in case of fire or flood, you can still access that in other places.