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You clearly have no clue what you're talking about.
->More than you imaging, but perhaps you just want to bully around and ignore the facts.
There's various multi-crypto currency wallets linked above,
->multi-crypto or all crypto as asked in the topic is only one and not various
which give you FULL control over your wallet, and where the so called "third party", who coded the wallet has no influence or power AT ALL, ( or access to your private keys).
-> which HAS full control over your private keys, passwords etc. you can´t be sure that the won´t be spied out . If you are interessted in storing large amounts of coins safely using only open source software without binary blobs a step in the right direction.
Otherwise you have to belive that you can buy security for money and trust those who sell it
f they go down, you should simply be able to export your private keys offline, and import them into a new wallet.
->Depends of how the keys are stored and if you can extract the key out of the container the wallet droped on your comptuer.
( In some cases they can't go down at all, see trezor & Nano for example. I actually think exodus can't go down either, unless all the nodes of every altcoin go down aswell.)
Exodus can´t go down, but could discontinue, sold to the wrong guys, get money to spy on you, pick a reason to use open source software of your choice.
Have a nice evening
and enjoy the input