As far as I know, BetFury's withdrawal fees for Bitcoin are not too high and solely cover the expenses of running the business.
I disagree with that. Betfury offers two options to withdraw BTC (fast and slow), and in both options, the withdrawal fee is too high. So for fast withdrawal, they ask for 25k sats(~$23), and for slow withdrawal, they ask for 7,5k(~$7). For comparison, the current BTC network fee is only 2 sats per byte.
The good thing is that Betfury has Cryptoswap, and many other alts are available there with more favorable withdrawal fees.
This could be only hurt if you do tend to make out some small amount withdrawal but if you are trying out to withdraw big ones then you wont care at all but still the fees are indeed high.
Based up on experience about withdrawal fees then the highest fees is on Stake. Based up into the sats/byte on which Betfury have then this is indeed high.
If they do have that internet exchange or swap then conversion to TRX will be the cheapest i suppose.
The bitcoin fee is too high indeed but I wouldn't swap to Tron. I used to do at all the time but since TRX went up so high in price, the fees are also quite high. Last time I converted all my coins I had on Betfury to USDT to withdraw as that had the lowest withdrawal fee. Need to recheck to make sure that is still the case.