If you want to store any altcoins then you can use Metamusk Browser Extension. You can hold more than one HUGE amount of altcoins here. But if you want to hold Bitcoin then Electrum wallet will be best for you. Because it is considered a Bitcoin secure wallet.
You meant Metamask wallet. Second is that someone should not hold huge amount of coins on an online wallet. If the amount of coins is huge and also for many coins and tokens, the best is to get a hardware wallet. One of the best hardware wallet that can be gotten is Trezor. Trezor is supporting bitcoin and many altcoins.
Although, if it is a bitcoin only wallet, Electrum can be used as a cold storage wallet. Also is Sparrow and some other reputed bitcoin wallet.
Very true but if you want to hold your huge funds on an online wallet, you would just have to be super duper careful or would you still say that no matter the carefulness you are prone to be hacked, or whatsoever? Like using Metamask, there are rules I follow like ensuring that I do not have any untrusted extension, I do not have any untrusted tabs open, I do not have apps that I do not know on my computer. These are the ways that I know one’s wallet can be hacked.