Liquidity (with sygnum, you get access to institutional liquidity pools), loans....etc.Not sure what other “service” you could need from an exchange in addition to exchanging crypto/fiat.
Specially with loans, you can get a large loan with very low interest rate and you can take an advantage of crypto trends and buy more coins with the loaned money, and pay the interest back from your profits. Been there and done that. very lucrative if you know what you are doing and you're doing this with a good exchange.