Bitcoin isn't the perfect protection against inflation,because the Bitcoin price is very volatile and there's no stable and increasing BTC price pattern,following the increasing monetary supply.The 2017 ATH might never be reached.
If the Bitcoin price is increasing following this pattern during the next 5 years:
2020-$10K 2021-$12K 2022-$15K 2023-$18K 2024-$21K 2025-$24
Then,I would say that Bitcoin would be a great protection against inflation.
However,this price pattern ain't gonna happen in the real world.
The price will have it's highs and lows in the next 5 years and long term price predictions are impossible.
The "Cantillion effect" will continue until the end of the fiat financial system.
Some would disagree with your statement, because facts and numbers do not lie. It is also true that BTC is very volatile, but we have seen that this is also the case with the stock market or with crude oil. Yet I find rather ridiculous statement that the new ATH may never be reached, since price should increase only x3 to get there.
Almost all periods in the past 11 years have been successful for investment, except for the short period in late 2017 and early 2018. According to statistics from CMC, Bitcoin ROI from 2013 is 5.604,01%, and I call that excellent protection against inflation. Maybe you should listen some smart people who predict price of BTC in past very precise, but it is much easier to listen to some so-called experts who say something different every day.