Well you brought GDP as argument, which just doesn’t have anything to do with the price of an asset. If you sell a lot and buy a lot GDP grows, but the price of that asset can still be the same at the end.
Getting back to your initial argument:
Since anonymity is a feature, any transactions will increase its value due to it being “used” more
This is just plain wrong, as I could just make myself rich according to that logic… I still need to have that FIAT-money, need to exchange it (in which case I have driven the price up), but now I have less FIAT, so either I have more FIAT to further drive the price, or well I need to cash out in which case I’ll drive the price down. If I just send crypto from one (anonymous) account to another it just does… nothing to the price…
That isn’t true, it is used albeit of course more for speculation, than FIAT.
Guess what, FIAT money like the dollar and euro are also assets, and the same is true for that as well. Though Inflation is usually controlled by central banks.