Since it runs on your LAN, you can block it entirely from the internet and use a VPN (WireGuard/OpenVPN) to view feeds. No cloud services. No Chinese servers. Maximum privacy.
The elephant in the room. Hikvision is a Chinese company (subject to NDAA concerns in the US). Their devices have "phone home" features via Hik-Connect. While you can disable P2P and use only LAN, the default setup often routes through Chinese servers. Many US government agencies ban Hikvision entirely. blue iris vs hikvision nvr