Whatever technical solutions can be made don't really matter unless normal people can and do use them correctly. In any case, simply setting up another non-phone computer to do the job of the smartphone doesn't change the fundamental issue, it can still break, or get stolen, or some account can get closed for spurious reasons.
We're all here to make our own decisions. We're all here to seek enlightenment. I've made it very clear that the decisions that I have made have placed me where I don't have the same issues as OP.
I'm enlightening OP, and everyone who reads these comments, I'm not "blaming" anyone.
You are offloading decisions to the consumer, decisions that the consumer shouldn't have to take. They should be solved by systems design already.
You are blaming them in your first sentence. You're both blaming and informing, your message would come off much more friendly without the first sentence.