I don't have much knowledge about this, but it's my personal opinion. if you are based in a country where gambling is legal, of course you must have a license so that you do not violate the laws and jurisdictions of that country.
By obtaining an official license to operate an online casino, it ensures that players make bets without risk, are credible and reliable.  in addition, you have met the standard criteria as set by a country. that way, of course we gambling fans, will not feel worried about our security as users.