If you care about this data then you would encrypt it at rest. Having encrypted it at rest there's a key, let's say it's a 256-bit AES key. So now when you throw away the 256-bit AES key the rest of the data is garbage, exactly as worthwhile as if you'd wiped it, but instantly.
A factory restore might take quite a lot longer, but as soon as that key is forgotten the data is gone.
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Don't wipe 128GB of flash.
If you care about this data then you would encrypt it at rest. Having encrypted it at rest there's a key, let's say it's a 256-bit AES key. So now when you throw away the 256-bit AES key the rest of the data is garbage, exactly as worthwhile as if you'd wiped it, but instantly.
A factory restore might take quite a lot longer, but as soon as that key is forgotten the data is gone.