Funny how this conversation started how crypto is slow and expensive, and now turned into slow and expensive is OK :P.
In a crypto world, you don't need to convert to Euros. Are we in a crypto world yet? No. Will we live in crypto world in the future? Maybe, when it's faster and cheaper ;).
For the common transactions people make, crypto is both slow and expensive. I can Zelle someone instantly, for free. In the EU, Australia, etc., bank-to-bank transfers are similarly instant. I don't know that Bitcoin etc. ever get to totally free in this fashion, and it's probably 99.9% of most people's money transfer usage.
For the uncommon transactions - like the $50k international transfer you mention - slow tends to be OK, and it's likely gonna have some expense either way.
Short version: In contrived scenarios, Bitcoin may come out on top, but that's not likely to convince many people.
How many "common transactions" do people use "money" for?
All "common transactions" use credit (even when you use a debit card). The banks approve transactions quickly, but reconcile those transactions slowly.
It'll be the same for any crypto that takes off but needs to reconcile slowly.
In a crypto world, you don't need to convert to Euros. Are we in a crypto world yet? No. Will we live in crypto world in the future? Maybe, when it's faster and cheaper ;).