The golden rule of choosing an exchange is to go with the most popular and 'trusted' exchange, don't touch small/unknown exchange if there's not enough reason to do it.
Trading BTC is obviously not a good reason to try an exchange with fairly low liquidity & reputation.
Fair, but trading pairs such as BSV/BTC have their volume almost exclusively on Delta.exchange, which leaves people little choice.
I would agree with the statement if it was BTC. As I said before, there are plenty of more reputable, established marketplaces with tons more liquidity when it comes to BTC/USD derivatives. But not for a lot of small cap altcoins that are only listed on delta.
Take a calculated risk, if you will. Don't put in too much.