The entire point here is that sheep do not need an overly protective mode. It's a false premise.

I know plenty of them. I help them navigate modern tech. I install fdroid on their phones. They lie on a continuum and none of them are going to turn on developer mode (or whatever BigTech wants to call it) because a stranger on the phone told them to.

There is a small sliver on the far end of the continuum that will do things like that. But in general they are sufficiently gullible that no measure that can be bypassed will ever work for them. They require a Fisher-Price device.

BigTech wants to hold that small sliver up as justification for their anticompetitive practices.