maybe ill try to explain my point again, so imagine....
BTC 21,000,000 / Current Circulating Supply / 18,648,793 BTC / Year 2020 / Projected Circulating Supply in 2030 following inflation rate 1.4% = 18,980,000 (for example)
BTC 21,000,000,000,000 / Current Circulating Supply / 18,648,793 BTC / Year 2020 / Projected Circulating Supply in 2030 following inflation rate 1.4% = 18,980,000 (for example)
It would be the same.
So it wont matter FOR US if its a fixed supply of 21 million, because during the course of our human lifespan bitcoin will still inflate at the same rate.
But for people born in say 2120, it will be an issue because there will only be 20 years left before in becomes deflationary, but for all of us born now it has no effect.
You only take one factor in your calculation. As vario mentioned above, even if inflation stays the same, there will be more and more coins that will enter the market, and eventually, the volume would drastically change. It will gradually become worthless (price will go down) and the purchasing power would decrease, just like fiat.
Do you think you'll be happy when your 1 BTC right now will be equal to 0.1 BTC in the next 10 years? I doubt you'll like that. You need to look at the long-term instead of the short-term effect.