Another reason I don't like Tangem is that you can only use it with their app, so there is no way to use any third party wallets.
In case Tangem company goes bankrupt there is good chance coins will be lost.
I get your concerns, but one important thing to note: even if Tangem shuts down, the wallet won't become useless. While the app itself isn't fully open source, Tangem has published their SDK on GitHub, so it's possible to build a custom app manually. You can do it yourself or ask a developer to help. The key point is that the private key is stored securely on the card itself, not in the app. So as long as you have the card, you can still access your funds even if the official app disappears.