The bitcoin amount is limited, it is not like any other currency (you can a lot from it that you even can't count). Also Miners of cryptocurrencies have to take fees for every transaction, like a commission for them.
That is why the Bitcoin fees are very high and the transaction can take around 24 hours or more so if you want to sell, try to sell earlier that the day you supposed to sell because it will take time.
I agree with you with you.
As far as I know the transaction fee was so high because the value of bitcoin is also high.
Aside from that it way of the owner to have a commission for every transaction you did.
It is the same as the tax added to our earning.
And it takes a lot time because of a long process in doing it to maintain the security for purpose of your bitcoin