This is WHY: every exchange that holds users BTC also have theirs fBTC.
So exchange have 3 options:
- ignore fBTC - but users can be angry (at least)
- allow to withdraw fBTC by users - need some coding on echange and make zero profit
- start BTC/fBTC market - need more than some coding but also make profit
So, exchanges that want profit (believing in fBTC futore or not) choose option 3.
i couldn't agree more