PoS coins have no creation cost. so those would actually follow your idea that its just a number(like fiat) where it has no cration cost, but gains value by people finding labour/goods to make swaps with it

but PoW coins actually have a cost that comes with its creation. and due to other features and benefits, they have utility too

fiat does not have the 'borrowers liability/security' you think it does. you are owed nothing when you hold a bank note

bank notes value does not come from its creation. but from someone else working to then give it value after creation in exchange for goods/services.
thus a simple medium of exchange with no underlying backing(Pos coins and fiat)

bitcoin has underlying backing right from its creation, which is then strengthened by the work to add more confirmations. and also new confirms when its being spent.

then.. it becomes used as a medium of exchange ontop of that where people swap labour, goods for it(like fiat)
so bitcoin has more to it than fiat does


i have bitcoin from 2012, and to undo the proof of its creation. it requires ~510,000 blocks to be undone to remove trace of my coin. and then another >510,000blocks to be rebuilt ontop to legalise that change into existence by overtaking the network
it costs over $240k to make a block right now
meaning it costs $5,691,784,177,413.87 redo all that work

i can destroy proof of your bank notes existence with a match, and your bank wont just give you another. you have no security

now if you want to think they are just number.. try it
take a bank note out of your pocket. and put it beside your screen
then find a random bitcoin on the network...

try and destroy the bitcoin, then light your bank note on fire... see which one survives and which one can be destroyed