Yea, for this particular situation where you’re wanting something safe and secure for long term storage, that is going to give you the most peace of mind because you had the most control over the process. For day to day use and small amounts, using something like the BlueWallet app to generate those wallets is fine. And even BlueWallet allows you to incorporate things like coin flips or dice rolls to create more entropy when creating those wallets. Coldcard does that too, but again does it all offline, whereas something like BlueWallet is doing this all in an online device.