A few reactions:

1) Sensitivity to inflation: if by that you meant that crypto prices go up when there's monetary inflation, I'd argue that's a form of inflation protection, just like for stocks, bonds, houses, etc. Any asset with inelastic supply will tend to go up in price whenever the currency supply goes up.

2) Contribution to inflation: if by "products benchmarked to USD" you meant stablecoins and the fact that their issuance contributes to inflation, I agree, to the extent the stablecoins are not 100% backed with actual USD. That said, stablecoins are still a drop in the ocean in terms of share of outstanding USD liabilities, so the contribution is minimal. In any case, my comment in this paragraph was not a reference to stablecoins but to volatile coins such as BTC and ETH.

3) Conversion to fiat: I disagree that the purpose of holding wealth in USD (if you are Argentinian) or in cryptoassets is defeated if you have to convert to local fiat for spending. As long as you are holding you are protected. And when you want to spend, you are only exposed temporarily until you acquire whatever good you want to acquire. The only problem is the potential triggering of a taxable event, but that's a separate issue.

More generally, I think the inflation resistance of crypto is self-evident per the immutable supply schedule. It may not appear so because of the incredible volatility of their price. But the volatility is just the market trying to figure out if indeed those assets will become a store of value. That is inherently speculative and it could all go to zero. But it wouldn't be because they are a poor inflation hedge, it would be because the market didn't believe they could become a safe store of value.