It must not have been safe to do so, but I actually did it some years ago, and then I was not really too informed about the risk that is related to giving out personal information so freely without minding the outcome. That's why I said that the reason some people make mistakes is due to a lack of proper information. It was after I joined the forum that I properly understood the dangers of KYC.
I hope the platform that you used was a trusted one, as at least in that instance the chances your information could be sold or stolen gets reduced in a dramatic way.
Still, it is important to avoid sharing that information as much as possible, so if there are platforms that you can use that do not ask you to pass any KYC check and that are trusted as well, then it is way better to use those platforms, as a way to reduce the chances of our information getting leaked by some reason or another.
There might still be some casinos that are only interested in having our information in their hands so that they can always use it to do whatever they want without any worries. Gambling is fun but when it looks like it's becoming too serious and unbearable, we can always quite even though while looking for another good platforms we can be using. There are so many bad casinos out there we need to avoid because they would always want to do everything to make sure that we are frustrated especially when we have funds in such platforms. It is always good for us to be wise and go for what we really want so we don't get cut out at the middle.