There are many sites that do not have any withdraw fees , u can use those instead
HOWEVER , those sites usually have a rollover requirement on deposit ranging from 100% to anywhere up
stake , as far as im aware has very low rollover required (10%) , so every site has pros and cons
Sportsbet doesn't charge any fee in both withdrawal and deposit additionally they didn't have any wagering requirements for your deposit in able to be withdrawn. I sportsbet most of the time for sports betting and never experience this inconvenience that you guys talking here.
So my question remains what did Stake do with the remaining $1.40

It is a big amount to go missing especially when some Sportsbooks don't charge anything.
They usually charge a flat rate fee to counter crypto volatility since they will only hold the crypto in there hot wallet. Those missing transaction you are looking for will go directly to there treasury fund to cover other withdrawal fee in case the standard transaction fee of Bitcoin increased due to network flood. They are using a flat rate withdrawal to save time on adjusting withdrawal fee whenever Bitcoin blockchain network become crowded.