> I often argue such things should be put in portfolios to show off skills,
Sure.
> This kind of academic or portfolio work is also clearly not what we're discussing because of course it has inherent value in just the creation.
You are no boss of mine, i discuss what i want. :p What you are saying here is exactly the point I am making. You only see the value of the software which is provided by its direct use. So much so that you don’t even want to discuss the alternative values and cide me for even bringing them up.
Imagine that you take steel bars and forge a garden fork out of it using blacksmithing techniques. There is value in that, in as much as the person who made it become a better craft person by doing so. Even if you can get a better fork at home depot for much cheaper.
> If you make it to do app and share it with me, I really don't care.
That is up to you. If you make a todo app and share it with me i will ask you what made you interested in making a todo app. But yeah a todo app is not a particularly inspiring thing in the grand scheme of things, so unless you are a very junior developer or you are trying some new technique you are unlikely to get much accolades for it.
But todo apps is not the only thing one can do. If you implement some cool artistic image filter, or write a process scheduler, or make an auto-router for pcb traces i will celebrate that with you even if there are better solutions out there. Because those are your “garden forks” and the skills you learned while making them can’t be taken away from you.