It’s the reason we have Miranda warnings.
SCOTUS was sick and tired of being bombarded with appeals from defendants who claimed not to know their rights, so they actually went case-shopping for one they could use to impose it as a universal rule. All to reduce their workload. Research it.
I know you are right. The sometimes ludicrous Miranda warnings are the result of defense attorneys sifting through loopholes and technicality hunts to get their clients off through appeal.