As far as I can see, your example is less of a benefit to early adopters, compared to the current supply growth.
Sure it is less, but there would still be a huge benefit and it would ensure many more early adopters and I suspect allow the network to grow bigger, spreading the overall benefit and encourage adoption over a longer period.
I suspect we are in a catch 22, growth in Bitcoin adoption will now = an increase in price of Bitcoin, that is good for savers but bad for economic growth and bad for new adopters.
Why? Why should supply grow at its highest rate at some random mid-point?
Good point, I don't know it should, but for that matter why should it start fast and fissile out in 4 year?
I think easy mining rewords encourage network growth, and adoption of Bitcoin, so I imagine the party would go on longer and provide more benefit to a larger user base.
With Satoshi's model of supply, we have one factor decided on from an educated guess: the halving rate (~4 years). With your model we have two such factors: 1. the mid-point (of highest monetary inflation) and 2. the growth rate before and after this point. Why not choose three factors that determine the supply, or maybe 18 factors? I think the point is that supply isn't that important, and - not the least - that each supply curve will have its advantages and disadvantages, and trying to predict these is futile. In any case I think we can spend our time improving the protocol in much more important aspects than wrt. to the supply curve.
You may be right. I won't move from Bitcoin because I am totally invested in it, I will be sad to see it stop growing because savers are reworded by saving - by that very nature saving discourages spending and disseminating Bitcoin's. The new curve would allow a competitor to Bitcoin to start and not discourage later adoption. Alas without it I will become a victim of my own savings and continue to hoard my Bitcoin's and hope you sell your first.