Maybe end to end encryption channels are used but if the government are interested in having those data they will impose many restrictions in order to have that data but i think Roobet has previously also stated that your data is safe with them and not shared with anyone.Security protocol must be followed but we should be careful at our end also.
When you sent and submitted your identity documents for KYC, you should accept that your identity documeng lost forever. It can be leaked or breached anytime in future. You can not control that and even a platform on which you submit your document can not control it completely too.
So afford personal data breach before you do KYC. A good platform will invest into security which is helpful to prevent data breach. However, they can not secure their database 100%.
That the future part is the scary thing. I could give it, and they could check it or inform anyone they have to, but then they could delete it and it would be much better. If they save it, and then keep on having it, who knows when it will be leaked or if it will be leaked? You will live with the fear that your KYC could be leaked anytime in the future, maybe 5 maybe 10 years down the line?
So that is the bad part, get it but delete it after you used it, that would be better. I guess there is a law that requires them to save it and store it somewhere in case it is ever needed again in the future, for people who are innocent now, but could commit crime later on.