So you can have some protection. The issue I see is that you NEED the Tangem app to unload that card. They disappear in the middle of the night that could be an issue.
You can't even get your private key from the card.
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-Dave
That's a huge concern for those looking to use Tangem cards as a long-term storage for crypto. Since you don't control the private key, you don't truly own the funds. This bearer instrument is only useful for small amounts of crypto or doing quick transactions between peers. If you're looking to store large amounts of crypto, then hardware wallets are your best option.
What I like most about the Tangem cards is their cheap price (and design) compared to other crypto wallets. They make great souvenirs or collectibles that might be worth a ton of money in the future (if they become extremely rare). The Tangem team should've made the app open source so that people who kept their cards for safekeeping, could use them in the future even if the company ceases operations in the long term.
As for the OpenDime, I don't think this will be a concern since data is stored locally on the device without the need to interact with a separate app to read the private key. You could hold your OpenDime for years without worries. The OpenDime could be a true winner in this regard, unless the Tangem team decides to provide an "exit route" to users if they decide to disappear in the middle of the night.
Having said that, I guess the point of these cards isn't really to be a long term HODL type device... more a way you can load up some coins and pass them onto someone in a relatively secure (offline) way.
Yeah. I wouldn't use Tangem cards for serious long-term storage of crypto, except for performing quick transactions with it. Different types of wallets have their unique purposes in real life. Those looking for a reliable long-term cold storage for their crypto will simply use a paper wallet or a hardware wallet, while those who want to send crypto offline quickly will use an OpenDime or Tangem card.
Nonetheless, hardware wallets are ten times better than the OpenDime but they're relatively expensive. People who cannot afford a hardware wallet could simply use an OpenDime over a software wallet for added security without breaking the bank. At least, we have many options to choose from.