People shouldn't learn whatever you consider important. A farmer saving in BTC should not waste time learning to audit psbts, it will literally give them zero value. They should use whatever open source hw wallet, ideally one that will keep stablecoins as well (no coldcard, it also isn't FOSS). He makes steaks and milk and people who are interested and good in computer security make wallets.
No reason for a farmer to make DIY wallets either.
I see this tendency often that people should learn whatever someone considers important. The beauty of Bitcoin is you can go as deep as you want. If people get self custody and non KYC, they're already much better off than most people and that's good enough. Now go make the 🥩.