Buying a second thing to unnecessarily duplicate functionality seems like a waste, even if the thing by itself would otherwise be a solid deal.

That depends on whether or not you'd consider "setting an example for your kids" in this particular way as necessary or not. If you think that's valuable, then this isn't an unnecessary duplicate. If not, then sure.

As opposed to a fancy gizmo that does everything but has to be replaced every three years due to lack of support?

1.) I replace phone when they are too broken, not on schedule.

2.) I need phone anyway. And even old flip phones had alarm. Phone with alarm does not need to be fancy at all.

Yes it is wanting money. Especially since I already own multiple device capable to do exact same thing.

I prefer to set example of not buying all the available crap. That one is more important all I all.