According to me for bitcoin wallet blockchain(dot)com is the best and secure.
It's a web wallet so anything that is in the surface of internet doesn't have an assurance of security but as per mocacinno said if there is/are dev who maintains the whole system properly will make that safe but still don't be confident.
I would combine two strategies :
1. Hardware wallet : You buy a hardware wallet and you store say 30% of you coins in that wallet. This will give you easy access to some of your coins.
2. Paper wallet : You store the remaining 70% of your coins in paper wallets. It is important that these paper wallets are created in the most secure method possible, before you store any coins on them. Search for guides on how to create secure paper wallets on this forum, because it has been discussed multiple times on this forum before.
Try to split the 70% into smaller amounts on different paper wallets and make a backup of these paper wallets.
I'm storing most of my coins on hardware wallet to be specific with nano ledger s.
the safest way is hardware wallet, but it's expensive.
Security isn't expensive if you have more than the price of what you buy, if you find it expensive then shift to paper wallets or if you have an extra laptop install a desktop wallet and use it as real hardware wallet.